A947 Route Study Report - Final - Aberdeenshire Council€¦ · Route Study Report Prepared for: Aberdeenshire Council Transportation & Infrastructure Gordon House Blackhall Road

Aberdeenshire Council A947 Parkhill to Banff Route Study Report

Prepared for: Aberdeenshire Council Transportation & Infrastructure Gordon House Blackhall Road Inverurie Aberdeenshire AB51 3WA Prepared by: Grontmij Spectrum House 2 Powderhall Road Edinburgh EH7 4GB T +44 (0)131 550 6300 F +44 (0)131 550 6499 E [email protected]

Report Status: Job No:

Name Signature Date

Prepared By: Ronan Lyng

31/03/11

Checked By: Stewart Craigie

31/03/11

Approved By: Stewart Craigie

31/03/11

© Grontmij 2010 This document is a Grontmij confidential document; it may not be reproduced, stored in a retrieval system or transmitted in any form or by any

means, electronic, photocopying, recording or otherwise disclosed in whole or in part to any third party without our express prior written consent. It should be used by you and the permitted discloses for the purpose for which it has been submitted and for no other.


EXECUTIVE SUMMARY ................................................................................................. I

1 INTRODUCTION ............................................................................................... 1

1.1 General ............................................................................................................. 1

1.2 Location ........................................................................................................... 1

1.3 Context and Methodology............................................................................... 2

1.4 Objectives ........................................................................................................ 5

2 DETAILED ROUTE INVESTIGATION .............................................................. 6

2.1 AADT and Vehicle Speeds .............................................................................. 6

2.2 Average Journey Time Survey ....................................................................... 7

2.3 Personal Injury Accident Data ........................................................................ 7

2.4 Geometry of Existing Route ......................................................................... 26

2.5 Overall Description of Existing Route ......................................................... 30

2.6 Bend Assessment ......................................................................................... 34

2.7 Existing Junction Layouts ............................................................................ 36

2.8 Existing Pavement ........................................................................................ 38

2.9 Existing Road Drainage ................................................................................ 41

2.10 Double White Line (Desktop) Survey ........................................................... 44

2.11 Existing Roadside Furniture ......................................................................... 45

2.12 Laybys ............................................................................................................ 47

2.13 Existing NESCAMP Mobile Camera Sites .................................................... 49

2.14 Recorded Maintenance/Minor Works ........................................................... 50

3 PARKHILL ...................................................................................................... 51

3.1 Traffic Flow and Vehicle Speeds .................................................................. 51

3.2 Personal Injury Accident Data ...................................................................... 53

3.3 Geometry of Existing Route ......................................................................... 54

3.4 Bend Assessment ......................................................................................... 54

3.5 Existing Junction Layouts ............................................................................ 55

3.6 Existing Pavement ........................................................................................ 55

3.7 Existing Road Drainage ................................................................................ 55

3.8 Double White Line Survey ............................................................................ 56

3.9 Existing Roadside Furniture ......................................................................... 56

3.10 Lay-bys .......................................................................................................... 56

3.11 Existing NESCAMP Mobile Camera Sites .................................................... 57

3.12 Recorded Maintenance/Minor Works ........................................................... 57

4 MAJOR PROJECT INVESTIGATIONS ........................................................... 58


4.1 General ........................................................................................................... 58

4.2 Assessment ................................................................................................... 58

5 THE 4 E’S ....................................................................................................... 62

6 IDENTIFIED PROBLEMS AND PROPOSED INTERVENTIONS .................... 64

6.1 Geometry ....................................................................................................... 64

6.2 Bends ............................................................................................................. 64

6.3 Junctions ....................................................................................................... 66

6.4 Pavement ....................................................................................................... 67

6.5 Drainage ......................................................................................................... 68

6.6 Double White Line Survey ............................................................................ 71

6.7 Lay-bys .......................................................................................................... 71

6.8 NESCAMP Mobile Camera Sites ................................................................... 73

6.9 Roadside Furniture ....................................................................................... 76

6.10 Urban Areas ................................................................................................... 79

6.11 Maintenance .................................................................................................. 79

6.12 Partnering ...................................................................................................... 80

6.13 Highway Asset Management ........................................................................ 80

6.14 Other Routes ................................................................................................. 80

6.15 The 4 E’s ........................................................................................................ 81

7 CONCLUSIONS .............................................................................................. 82

REFERENCES ............................................................................................................. 84


APPENDIX A – DRAWINGS

APPENDIX B – BEND RISK ASSESSMENT

APPENDIX C - GEOMETRY ASSESSMENT SPREADSHEETS

APPENDIX D - JUNCTION VISIBILITY SURVEY

APPENDIX E – PAVEMENT ASSESSMENT

APPENDIX F – DOUBLE WHITE LINE SURVEY

APPENDIX G - VEHICLE RESTRAINT SYSTEMS ASSESSMENT

APPENDIX H – LAY-BYS ASSESSMENT

APPENDIX I - MOBILE CAMERA SITES ASSESSMENT

APPENDIX J – MAINTENANCE RECORDS

APPENDIX K - ‘A DESCRIPTION OF THE INPUTS DELIVERED TO YOUNG

DRIVERS AND ADULTS BY ROAD SAFETY GRAMPIAN’

APPENDIX L - POST-INSTALLATION REVIEW OF THE EFFECTIVENESS OF

THE PVR COUNTERS

APPENDIX M - ROSY ROAD SYSTEM

APPENDIX N - EURORAP RISK RATING MAP

APPENDIX O - WARD MEMBERS/COMMUNITY COUNCILLORS

CONSULTATION


List of Tables Table 1.1 - 2020 Accident Reduction Targets ............................................................................... 2 Table 2.1 - AADT and average speeds ......................................................................................... 6 Table 2.2 – Permanent Counter Data ............................................................................................ 6 Table 2.3 – Average Journey Time Survey Northbound ................................................................ 7 Table 2.4 - Average Journey Time Survey Southbound ................................................................ 7 Table 2.5 - Average Journey Time Survey Return ......................................................................... 7 Table 2.6 - Scottish road safety targets to 2020, with milestones at 2015; applied to A947 ........... 8 Table 2.7 - Reported Personal Injury Accidents by Year and Severity ........................................... 8 Table 2.8 - Reported Personal Injury Accidents by Scheme Section and Severity ........................ 8 Table 2.9 – Achieved Accident Reduction (Scotland) .................................................................... 9 Table 2.10 – Achieved Accident Reduction (‘A’ class roads; Grampian; A947) ............................. 9 Table 2.11 - Achieved Accident Reduction Targets (A947) ......................................................... 10 Table 2.12 – A947 accident rates v. investigatory level, set 1 ..................................................... 16 Table 2.13 - A947 accident rates v. investigatory level, set 2 ...................................................... 17 Table 2.14 - A947 accident rates v. investigatory level, set 3 ...................................................... 18 Table 2.15 – A947 Top 20 Accident Causation Factor Combinations .......................................... 23 Table 2.16 – A947 Urban Accident Rate ..................................................................................... 26 Table 2.17 - Minimum Horizontal Design Parameters ................................................................. 28 Table 2.18 - Minimum Vertical Design Parameters ..................................................................... 28 Table 2.19 - Visibility Distances .................................................................................................. 29 Table 2.20 – Major Junctions Assessment – Existing Provision .................................................. 38 Table 2.21 – Visibility Distances (as per TSM Ch.5) .................................................................... 45 Table 2.22 – Lay-by Siting Criteria .............................................................................................. 47 Table 2.23 – Lay-by Recommended Spacing .............................................................................. 48 Table 2.24 – Existing Lay-bys ..................................................................................................... 48 Table 2.25 – Existing Slow Moving Vehicle Lay-bys .................................................................... 49 Table 2.26 – Existing Mobile Camera Site Locations .................................................................. 50 Table 3.1 - Parkhill Accident Numbers by Severity (2005-2009) ................................................. 53 Table 3.2 - Major Junctions Assessment – Existing Provision .................................................... 55 Table 3.3 – Parkhill Existing Lay-bys ........................................................................................... 57 Table 4.1 – Major Project Investigations Accident Analysis ......................................................... 60 Table 4.2 – Major Project Investigation Cost Benefit Analysis ..................................................... 61 Table 6.1 - Potential Areas of Improvement ................................................................................ 64 Table 6.2 – Bend Categories, associated Remedial Measures and Costs ................................... 65 Table 6.3 – Total Indicative Cost of Bend Mitigation Measures ................................................... 65 Table 6.4 – Major Junctions Assessment – Recommendations ................................................... 66 Table 6.5 – Proposals for lay-bys ................................................................................................ 72 Table 6.6 – Proposed Slow Moving Vehicle Lay-bys ................................................................... 73 Table 6.7 – Proposed Mobile Camera Site Locations .................................................................. 76 Table 6.8 – Suggested Clear Zones and associated Accident Reductions .................................. 79


List of Figures Figure i: Scheme Location Plan ...................................................................................................... i Figure 1.1: Scheme Location Plan ................................................................................................ 1 Figure 1.2: Road Safety Framework Process ................................................................................ 4 Figure 2.1: Comparing accidents (2000-2009) ............................................................................ 11 Figure 2.2: Comparing accidents (2000-2004; 2005-2009) ......................................................... 11 Figure 2.3: Accident numbers by Daylight/Darkness ................................................................... 12 Figure 2.4: Accident numbers by Weather/Road Surface Condition ............................................ 12 Figure 2.5: Accidents by month ................................................................................................... 13 Figure 2.6: Accidents by day of the week .................................................................................... 14 Figure 2.7: Accidents by time of day ........................................................................................... 15 Figure 2.8: A947 Primary Accident Causation Factors ................................................................ 21 Figure 2.9: A947 Top Ten Accident Causation Factors ............................................................... 22 Figure 2.10: A947 Accident Contributory Factors Classification .................................................. 24 Figure 2.11: A947 Accident Primary Contributory Factors Classification ..................................... 25 Figure 2.12: Junction visibility at Junction39 ............................................................................... 37 Figure 2.13: Junction Visibility at Junction 18a ............................................................................ 37 Figure 3.1 – 2012 Do Something AM and PM Peak Traffic Flows ............................................... 52 Figure 3.2 – 2012 Do Minimum AM and PM Peak Traffic Flows .................................................. 52

Aberdeenshire Council i A947 Parkhill to Banff Route Study Report

EXECUTIVE SUMMARY This report is the result of a route study undertaken by Grontmij between September 2010 and March 2011. The route study was commissioned by Aberdeenshire Council, in association with Nestrans. The A947 is a rural ‘A’ class road between Dyce, to the north-west of Aberdeen city, and Banff in Aberdeenshire. The route is approximately 61km in length and is generally orientated in a southeast-northwest direction. It passes through the towns of Newmachar, Oldmeldrum and Turriff. The sections of the route that pass through the above named towns are not included within the route study. A general scheme location plan is shown in Figure i below.

Figure i: Scheme Location Plan

Due to the length of the route the scheme has been divided into the following sections:

Section 1: Parkhill to Newmachar Section 2: Newmachar to Oldmeldrum Section 3: Oldmeldrum to Turriff Section 4: Turriff to Banff

The scope of the project was extended in length to cover the section of road between Parkhill and the River Don (County Boundary) – this had been originally omitted as it is part of the proposed Aberdeen Western Peripheral Route.

A947

Aberdeenshire Council ii A947 Parkhill to Banff Route Study Report

Taking into account the 2020 Scottish Government set accident reduction targets the route study has been undertaken with an evidence-led holistic approach which should result in the adaptation of a combination of engineering measures, higher visibility enforcement and targeted education and information. The objectives of the route study are as follows:

• Taking a holistic approach to analysing and assessing existing route conditions; • Identifying measures (Engineering; Enforcement; Education; Encouragement) which could

enable the reduction in accident numbers to meet Scottish Government identified 2020 targets;

• Promoting a partnering approach amongst key stakeholders across the route. The approach taken throughout the route study has been primarily one advocating the application of Route Treatment. The use of the Single Site Action (on its own) approach is not appropriate to the A947 as there may be a high probability of accident migration. This therefore means that the route study can be considered both reactive (to casualties) and proactive, as areas with little/no history of accidents are still considered for route improvements based on the idea of taking a holistic consistent approach to route safety. There are three major project investigations which are the subject of single site action and are dealt with in three separate Preliminary Design Reports, although the identification and selection process of these is detailed within this report. The A947 route, a typical rural ‘A’ class route, is characterised by many bends, frequent minor and agricultural accesses and poor visibility. The 85th percentile speed is high, ranging between 57 and 67mph. Over the review period of 2005-2009 there were 147 recorded accidents within the original limits of this study, including 12 fatal, 28 serious and 107 slight (a further three were recorded at Parkhill – one serious and two slight). In comparison with the previous five year period, although the number of serious accidents has decreased slightly, the number of fatal and slights accidents increased (the total number of accidents increased from 135 to 147). The latest accident information (from 2008-2010) also reveals that the situation on the A947 is worsening and the accident rate is increasing. This is against the backdrop of decreasing accident rates on similar roads across Scotland.

Although the overall accident rate for the A947 (21 accidents per 100 million veh-kms) is below the national investigatory level (30) the rate for fatal accidents is almost 50% higher. Section 3’s fatal accident rate is more than 200% higher than the investigatory level whereas Section 4 displays rates almost 50% higher for both overall (43 accidents per 108 veh-kms) and fatal accidents. The accident severity ratio is higher than the investigatory level in Sections 1 and 3 however it should also be considered that the overall accident severity ratio for the route (0.26) is marginally below the investigatory level of 0.27. It is apparent that the primary safety concern across the entire length of the A947 route is bend-related accidents. On average, the accident rate relating to bends for the route is 243% above the investigatory level. Of the 147 accidents occurring 71 were bend related. Other concerns of note are the high values over the investigatory level for accidents involving only one vehicle (114% above) and wet roads (45%; icy/snowy roads are also 30.3% above the investigatory level). These are, in many cases, related to each other and to inappropriate speeds.

Aberdeenshire Council iii A947 Parkhill to Banff Route Study Report

For accidents involving only one vehicle the top 4 recorded causation factors were loss of control (21%), slippery road (18%), travelling too fast for conditions (9%) and careless/reckless/in a hurry (5%). For accidents involving wet/icy/snowy conditions the top 4 recorded causation factors were loss of control (20%), slippery road (19%), travelling too fast for conditions (11%) and careless/reckless/in a hurry (6%). The accident contributory factors somewhat contradict the expected factor contribution for accidents as determined by RoSPA’s Rural Road Environment Policy Paper (2010). On the A947 the road environment factors (29%) contribute to a far higher percentage than may be expected and human errors account for 64% of the primary contributory factors. Taking into account the recorded accident data and analysed route geometry eight additional (to those previously identified within the major project investigation selection process) specific areas of the route were identified which could be subject to further investigation and possible improvement. At Parkhill, due to capacity problems consideration could be given to upgrading the junction with the B977, should the Aberdeen Western Peripheral Route be delayed any further. Consultations with key stakeholders and several site visits revealed that there is little or no consistency in the current provision for bend-related signage or road markings. Considering the scale of bend-related accident numbers and the apparent lack of current consistency of bend awareness a bend risk assessment has been produced for this report. The results of the bend assessment assign categories to each of the bends along the route. It is recommended that in the first instance, as a minimum, the remedial measures assigned within these categories are applied to each categorised bend (at a cost of £177,000). It is also recommended that the bend assessment process be completed by the undertaking of on-site evaluations of the bends to determine and/or confirm remedial measures applicability. The majority of the junctions on the A947 do not comply with current standards in regard to visibility. In many cases the visibility can be improved by modifying verge maintenance and providing ‘clear zones’ adjacent to the carriageway. It is unlikely, in most cases, that physical engineering works may be advantageous. Therefore it may be desirable that all junctions be either signed or junction marker posts used to improve their conspicuity. The existing pavement condition was assessed using the most recent SCRIM and SRMCS data. The SRMCS data generally revealed that approximately 75% of the A947 route is classified as in a satisfactory state of repair, approximately 21.5% is in need for further maintenance and/or monitoring and approximately 3.5% requires maintenance treatment. The SCRIM values reported were quite variable with considerable lengths below the Investigatory Levels by varying amounts. Although it is possible to identify areas where the SCRIM value is low, indicating the road may benefit from re-texturing or surface dressing, other information (such as the type and condition of the existing pavement construction) may be required to determine definitively whether the surface is suitable for either of these treatments. It is recommended that

• a review of the SCRIM surveys carried out to date, the planning and methodology adopted so that future surveys can be planned and adjusted on a rolling basis.

• all lengths where there is a SCRIM deficiency of 0.05 CSC units or greater be considered for Surface Dressing or re-texturing.

• all lengths where there is a SCRIM deficiency of 0 to 0.05 CSC units or greater be investigated further to determine if and when they should be treated.

• the section lengths where the SCRIM values are greater than 0.05 CSC units above the IL require no treatment at present.

Aberdeenshire Council iv A947 Parkhill to Banff Route Study Report

The drainage on the A947 requires improvement throughout, with new gulley and verge drainage provision being highlighted as the main items required. General maintenance of existing drainage items, with gullies and drainage pipes cleaned, any grass verges and channels vegetation cleared may improve the existing drainage along the A947. A desktop double white line survey was undertaken in the development of the report. It was agreed that a site visit to complete the process may be undertaken at a later stage (during summertime). Any proposed amendments to the existing provision of solid lines are based purely on the provision of any new lengths of or extensions to existing solid white lines. As part of the informal partnering both Aberdeenshire Council and Grampian Police were consulted during the process and proposals were drawn up with a view to minimising driver frustration along the route. Another of the aims of the route study that may assist in accident reduction is the promotion of the A947 as a ‘self-explaining’ road. These roads seek to make the actions of road users more predictable through presenting the road clearly and unambiguously, offering few distractions and making drivers clearly aware of the layout of the road (including junctions and bends) and the speed that could be reasonably driven. One of the concepts of self-explaining roads is ‘Forgiving Road Sides’, and the intention within the A947 route study is to promote Forgiving Road Sides where practicably reasonable. The theory of forgiving roadsides is the reduction of the numbers of and severities of accidents caused by vehicles leaving the carriageway, and hitting objects (eg. trees). As such 2m verges are proposed which may increase visibility, and all vehicle restraint systems, signposts etc are recommended to be passively safe. It is recommended that a review be undertaken of all existing directional signs in order to ensure that the concept of a self-explaining road is maintained. Vehicle Restraint Systems have been assessed and proposals include the potential adoption of more aesthetic barriers (eg. Nature Rail) and protective skirts to protect motorcyclists. Additional lengths of barrier have been identified at a total cost of approx. £243,000. It is also recommended that Junction Marker Posts be installed throughout the scheme at all unsigned junctions. This may improve the conspicuity of vehicles leaving the junction and further promote the A947 as a self-explaining route.

The A947 currently has 14 existing lay-bys (2 at Parkhill) and 5 existing slow-moving vehicle lay-bys (slow-moving vehicle lay-bys are used to encourage slow moving vehicles, agricultural machinery, HGV’s etc., to pull in to allow convoys of traffic to pass. This ultimately reduces driver frustration in areas where there are limited over-taking opportunities). Of the original 14 lay-bys 8 are proposed to be retained (including one extension), 5 relocated to new sites (including one relocated to existing slow moving vehicle lay-by) and there is one new lay-by proposed. This is based on achieving safer lay-bys that are closer aligned to current standards. From the original 5 slow moving vehicle lay-bys 3 have been retained (1 of which to be used as a conventional parking lay-by), 2 relocated and there is also 1 new one proposed.

There are currently 14 existing NESCAMP mobile camera enforcement sites along the A947 and they are generally located at existing lay-bys or within the carriageway verge. An assessment of the existing camera sites was undertaken in compliance with the guidance set out in the Scottish Safety Camera Programme Handbook. The majority of the existing mobile sites are located in undesignated areas and to comply with the guidelines a number of existing mobile sites are proposed to be moved to safer locations, where the appropriate visibility and conspicuity

Aberdeenshire Council v A947 Parkhill to Banff Route Study Report

requirements are met. In partnership with both Grampian Police and NESCAMP a range of proposals including new sites and the modification of existing lay-bys in order to accommodate a number of additional mobile safety camera sites have been made. A total number of 18 mobile camera sites are proposed; of these, 8 existing sites may be retained, 6 may be removed and there are 10 proposed new sites. In reviewing the existing provision of mobile camera sites it was found that the associated signage needs to be upgraded to promote the scheme as a ‘self-explaining road’. Therefore the erection of associated ‘Gateway-type’ terminal and repeater signing providing a consistent message at regular intervals along the full route is recommended. In order to aid effective enforcement of the A947, the installation of PVR (Per Vehicle Record) counter data is recommended. This counter data provides a recorded set of specific information for every vehicle that passes the counter that is set in the carriageway at specific points along the route. This information can indicate the speed limit at the specific site and the two-second following distance as well as the number of vehicles exceeding the set speed limit. Once analysed this information specifically aids the management and specific targeting of enforcement along the route. It is evident from the assessments undertaken throughout the study that general road maintenance needs to be improved along the route. Apart from the drainage and pavement maintenance the following recommendations are also made:

• that trees and hedges are cut back as far and as low as possible. • due to the issues highlighted with regard to visibility along the route it is also imperative

that verge vegetation maintenance is prioritised as appropriate throughout the year. • that consideration be given to studying the appropriateness of applying roadside clear

zones to the A947 (or sections of). In order to promote road safety related education Road Safety Grampian actively visits schools, colleges, universities and a substantial number of local businesses to deliver a wide spectrum of effective and innovative Road Safety presentations. One specific initiative of particular relevance to the A947 is the North East School Transport Safety Group’s The Bus Stop! Campaign which was initiated following the deaths in 2008 of two Aberdeenshire school pupils after getting off school transport, including one on the A947. This campaign has been designed to help highlight the potential risks when getting off school transport and the dangers of distraction in this situation. These initiatives should be continued, promoted and further extended to specifically target academies that are local to the A947. Although accidents relating to drink or drug driving or fatigue are few on the A947 it is recommended that key strategies within ‘Tomorrow’s Roads – Safer Roads for Everyone’ be continued within Aberdeenshire (it is noted that Road Safety Grampian currently run drink/drug driving campaigns, and that drink-driving rehabilitation schemes are sometimes offered to offenders). As some of the key factors linked to accidents on the A947 are driving too fast for the conditions and bends it is recommended that a publicity campaign for the A947 be developed based on the campaign suggested by Noble Denton Bomel (2009) – ‘Are you around the Bend?!’, highlighting the perils of driving round rural bends. It is also recommended that a series of road safety boards along the route be installed along the A947. Such boards can include for example, as a stark reminder to drivers, the number of fatalities on the A947 in the last five years.

Aberdeenshire Council vi A947 Parkhill to Banff Route Study Report

One of the successes already widely acknowledged amongst the key stakeholders was the open consultation that was undertaken, that effectively enabled an informal partnership amongst the parties. It is therefore recommended that in the interest of road safety and general highway management (including records) on the A947, in the first instance, a formal partnering arrangement be founded. This may enable the successful review, prioritisation and implementation of the recommendations included within this report. Such an arrangement may also ensure that the knowledge gained and relationships built may be maintained. It may also provide a firm base for any future route studies; and it could be extended as part of an overall network management team. This may benefit all parties through the facilitation of knowledge/information transfer; the potential joint-funding arrangements for projects; highway maintenance; and accident remediation. Available records of recent maintenance/minor works along the route were provided by Aberdeenshire Council, but they appear to be inconsistent with each other. The information provided about the works and its subsequent usefulness to the route study is minimal. It is highly recommended that an all-in asset management database system be fully implemented and integrated within the entire Transportation and Infrastructure Service of Aberdeenshire Council, in order to provide a highly efficient, accessible planning tool that encompasses a reliable, capacious and flexible road database; a maintenance planning module; a facility for implementing and administering digging within the highway network; pavement design; and a GIS facility. A review of the EuroRap Risk Rating Map and consultation with Aberdeenshire Council’s Road Safety Engineering Unit revealed that the highest risk ‘A’ class roads within Aberdeenshire were confirmed to be the following:

A957 Stonehaven to Crathes 73 accidents per 100 million veh-kms A98 Fraserburgh to Fochabers 28 accidents per 100 million veh-kms A980 Banchory to Alford 27 accidents per 100 million veh-kms

The highest risk ‘B’ class roads within Aberdeenshire were also confirmed to be the following: B977 Kintore to Balmedie 40 accidents per 100 million veh-kms B9077 Glebe Cottages (A957) to Maryculter (B979) 32 accidents per 100 million veh-kms It is therefore recommended that these ‘A’ class routes be considered as the subjects of comparable route studies, with a priority on the A957 and A98 routes. It is also recommended that, in the case of further delays to the procurement of the Aberdeen Western Peripheral Route, the B977 be the subject of a comparable route study.

Aberdeenshire Council 1 A947 Parkhill to Banff Route Study Report

1 INTRODUCTION

1.1 General

This report is the result of a route study undertaken by Grontmij between September 2010 and March 2011. The route study was commissioned by Aberdeenshire Council, in association with Nestrans. The project comprised three principal elements, namely: Data Collection; Route Analysis; and Major Project Investigation. This report will reflect on the collated route information and the results derived from its analysis. Recommendations for safety improvements will be identified, including three Major Project Investigations which may then be the subject of separate independent preliminary design reports.

1.2 Location

The A947 is a rural ‘A’ class road between Dyce, to the north-west of Aberdeen city, and Banff in Aberdeenshire. The route is approximately 61km in length and is generally orientated in a southeast-northwest direction. It passes through the towns of Newmachar, Oldmeldrum and Turriff. The sections of the route that pass through the above named towns are not included within the route study. A general scheme location plan is shown in Figure 1.1 below.

Figure 1.1: Scheme Location Plan

A947


Due to the lengthy extent of the route the project has been divided into four distinct sections; each separated by a town. The sections are, therefore, as follows:

Section 1: Parkhill to Newmachar Section 2: Newmachar to Oldmeldrum Section 3: Oldmeldrum to Turriff Section 4: Turriff to Banff

The scope of the project was extended in length to cover the section of road between Parkhill and the River Don (County Boundary) – this had been originally omitted as it is part of the proposed Aberdeen Western Peripheral Route. This section (‘Parkhill’) will therefore be reported separately, within this report, to the rest of the route.

1.3 Context and Methodology

There have been road safety concerns about the A947 for some time. In 2009 a route analysis ‘primary study’ was undertaken that identified some possible minor improvement works packages along the route. The report also summarised that despite a number of engineering measures being implemented by Aberdeenshire Council in recent years significant issues remain with regard to poor continuity of signing and lining, inadequate signing of bends and poor maintenance. The ‘primary study’ was based on accident reduction targets as set out in Aberdeenshire Councils Road Safety Plan, which itself was derived from 2010 government targets. Scotlands Road Safety Framework to 2020 (The Scottish Government, (2009), “Go Safe on Scotland's Roads It's Everyone's Responsibility”) has revised targets for 2020 (and interim targets for 2015), as shown in Table 1.1 below. Table 1.1 - 2020 Accident Reduction Targets

"Road safety priorities should be statistically led from reliable crash and casualty data; focused on reducing the number of road casualties requiring hospital treatment and set to give greater priority to killed or serious injury crashes over slight or non injury crashes" (Scotlands Road Safety Framework to 2020). Taking this into account


the route study has been undertaken with an evidence-led holistic approach which should result in the adaptation of a combination of engineering measures, higher visibility enforcement and targeted education and information (following best practice as suggested in the figure below). This approach is commonly referred to as the 4 E’s – engineering, enforcement, education and encouragement. Engineering will be dealt with as detailed below, encapsulating the assessment of the existing route and identification of possible suitable solutions. Enforcement has been considered throughout the route study particularly within the provision of specific engineering measures. Extensive consultation with both Grampian Police and the North East Safety Camera Partnership (NESCAMP) has been undertaken, and their respective views have been sought and considered. Specific provision, for which advice was sought, includes the Double White Line Survey and provision of enforcement measures along the route. As noted by RoSpa (2010) the enforcement interventions should be intelligence led with an overall objective of providing visible policing to encourage road users to drive to more appropriate speeds. Education will be considered, in brief, in the following sections. The Road Safety Officer for Aberdeenshire was consulted for this project. Encouragement has been promoted within this report through each of the above approaches. Engineering measures to enhance the route as a ‘self-explaining’ road are intended to encourage drivers to adopt a more suitable speed and be more aware of their environment and surroundings. The enforcement measures that are highly visible, and regular and consistent in both placement and operation provide incentive for drivers to adapt a more sensible approach to driving. Specific education and encouragement programmes are suggested with the aim of altering and improving the behaviours of all road users.


Figure 1.2: Road Safety Framework Process

Figure 1.2 above, from Scotlands Road Safety Framework to 2020, highlights the importance of consultation and partnering. This study has endeavoured to bring together as a partnership the key stakeholders along the route from data collection stage through to assessment and recommendations. The following bodies have been consulted: Aberdeenshire Council (various departments); Grampian Police; NESCAMP; Grampian Fire and Rescue Service; and Road Safety Grampian. Due to programme constraints it was not possible to carry out public consultation, however comments were sought from Ward Members/Community Councillors along the route. Their responses are contained within Appendix O. As reported by DfT (2006) in “A Road Safety Good Practice Guide” four strategic approaches to road safety are generally adopted:

Single site action – addressing a specific site with a much higher than average concentration of accidents of a particular type Mass action – addressing all locations having a similar accident problem over the whole area under consideration using proven remedial measures Area action – addressing a number of problems over a network of roads in one part of the total area under consideration Route treatment – addressing a number of problems on one or more routes


The approach taken throughout the route study within this report has been one advocating the application of Route Treatment. The use of the Single Site Action (on it’s own) approach is not appropriate to the A947 as there may be a high probability of accident migration. This therefore means that the route study can be considered both reactive (to casualties) and proactive, as areas with little/no history of accidents are still considered for route improvements based on the idea of taking a holistic consistent approach to route safety. There are three major project investigations which are the subject of single site action and are dealt with in three separate Preliminary Design Reports, although the identification and selection process of these is detailed within this report. This approach is based on the premise that as rural accidents are usually widely and thinly spread, a widespread, low-cost treatment approach to specific accident problems will generally be more cost-effective than treating a small number of individual sites, although sometimes more expensive treatment will be justified at certain locations but this will often be to alleviate capacity problems. The DfT (2006) also encourage the addressing of accidents at bends and junctions in order to reduce rural accidents and achieving national casualty reduction targets. Reducing speeds that are inappropriately high for the conditions may help to tackle accidents involving ‘loss of control’, and lack of awareness of these hazards. These types of accidents are considered within the report. It should be noted that a speed limit review of the route has not been undertaken as part of this study. Grontmij produced a Banff, Buchan and Buchan Areas Speed Limit Review in 2010 which considered specific settlements along a section of the A947 between Banff and Plaidy. The remaining speed limit reviews to be undertaken on the A947 were programmed to be carried out by Aberdeenshire Council.

1.4 Objectives

The objectives of the route study are as follows: • Taking a holistic approach to analysing and assessing existing route

conditions; • Identifying measures (Engineering; Enforcement; Education; Encouragement)

which could enable the reduction in accident numbers to meet Scottish Government identified 2020 targets;

• Promoting a partnering approach amongst key stakeholders across the route.


2 DETAILED ROUTE INVESTIGATION

2.1 AADT and Vehicle Speeds

Table 2.1 below shows the average speeds and traffic flows recorded for each section of the A947. These were received from Aberdeenshire Council in August and September 2010. Three of the counters are permanently fixed counters (South of Newmachar; North of Fyvie; North of Turriff) whilst records are available from a further three temporary counters (Birkenhills; Whiterashes; Hattoncrook). Table 2.1 - AADT and average speeds

The results for the volumes and speeds taken from the 7-day temporary counter at Hattoncrook are further supported by the data obtained from the nearby temporary counter at Whiterashes. This counter (June 2009) recorded an average AADT of 8677 with an 85th percentile speed of 56.4. It should be highlighted that the speed at North of Turriff is presented as mean speed only. This, by correlation with the other counter data, may suggest that the 85th percentile speed may be above 60mph. For the permanent counters the following AM and PM peak flows and speeds were recorded: Table 2.2 – Permanent Counter Data


2.2 Average Journey Time Survey

An average journey time survey was undertaken on the route by Streetwise in September 2010. This comprised three non-peak return drive-through journeys from the A947/ Riverview Drive (Dyce) junction to the A947/ A98 junction at the north end of the scheme. The results of the survey are shown in Tables 2.3 to 2.5 below. Table 2.3 – Average Journey Time Survey Northbound

Table 2.4 - Average Journey Time Survey Southbound

Table 2.5 - Average Journey Time Survey Return

2.3 Personal Injury Accident Data

2.3.1 General Accident Information

As stated in Scotlands Road Safety Framework to 2020 (The Scottish Government, (2009), “Go Safe on Scotland's Roads It's Everyone's Responsibility”), Scotland's Road Safety Vision is:- "A steady reduction in the numbers of those killed and those seriously injured, with the ultimate vision of a future where no-one is killed on Scotland's roads, and the injury rate is much reduced." The Framework sets out new road safety targets for 2020 (with interim targets set out for 2015) and reports on the previous targets (for 2010). Table 2.6 below highlights the accident reduction targets for these periods and displays adapted targets for the A947, based on the accident information received for the period 2005-2009.


Table 2.6 - Scottish road safety targets to 2020, with milestones at 2015; applied to A947

2.3.2 Reported Accident Data

Reported Accident Data, as obtained from the Stats 19 forms, was supplied by Aberdeenshire Council for the period 01/01/05 to 31/05/10. For the purposes of consistent reporting the considered review period shall be 01/01/05 to 31/12/09. During this five year review period, 147 personal injury traffic accidents (PIAs) were reported on this 61 km (approx.) review length. It should be noted that accidents recorded within the town boundaries of Dyce, Newmachar, Oldmeldrum, Turriff and Banff were omitted from these records. These accidents are detailed on accident factor grids - see Appendix A (further information is provided below). They are summarised by year and severity in Table 2.7 below: Table 2.7 - Reported Personal Injury Accidents by Year and Severity

The accident numbers are also summarised below by scheme section. Table 2.8 - Reported Personal Injury Accidents by Scheme Section and Severity


2.3.3 Comparison of A947 against stated achieved reduction targets

Tables 2.9 to 2.11 below have been compiled taking information from “Reported Road Casualties Scotland 2008”, and include the 2010 accident reduction targets and the reported achievements for Scotland (all roads), Scotland (Local Authority A class rural roads) and Grampian (Local Authority A class rural roads). For relevance and comparison calculated figures are also shown for the A947. Table 2.9 – Achieved Accident Reduction (Scotland)

Table 2.10 – Achieved Accident Reduction (‘A’ class roads; Grampian; A947)


Table 2.11 - Achieved Accident Reduction Targets (A947)

According to “Reported Road Casualties Scotland 2008” by 2007 Scotland had achieved a 45% reduction in KSI, a 67% reduction in child KSI and a 35% reduction in the slight casualty rate. From a peak of 892 road deaths in Scotland in 1969, the number of fatal casualties fell to 281 in 2007. This is set against a picture of increasing volumes of traffic with vehicle kilometres rising 16% over the previous ten years. What is evident from the above tables, and contrary to Scottish and indeed Grampian (Grampian has since been split into Aberdeen City Council, Aberdeenshire Council and Moray Council) statistics and trends, the A947 is performing poorly with regard to road safety and meeting set reduction targets. More worryingly, the number of fatal accidents increased by almost 50% whilst falling considerably throughout the rest of the country. In relation to the 2010 reduction targets the A947 is failing to meet these in the cases of KSI and slight accidents. In order to obtain a better understanding of the trend of accidents on the A947, reported accident data was also assessed for the period 01/01/2000 to 31/12/2004. During this five year review period, 135 personal injury traffic accidents (PIAs) were reported on this 61 km (approx; 54.2km from original scheme start and end points outwith urban centres) review length. For consistency, accidents recorded within the town boundaries of Dyce, Newmachar, Oldmeldrum, Turriff and Banff were omitted from these records. Comparing the two periods (2000-2004 and 2005-2009), see figures 2.1 and 2.2 below, the A947 evidently contradicts the trend of decreasing accident numbers (across severities) across Grampian (Aberdeenshire) and Scotland; and is clearly not meeting the targets set out in the Scottish Government’s Road Safety Framework.


Figure 2.1: Comparing accidents (2000-2009)

Comparison of Accidents between period 2000 and 2009

0

5

10

15

20

25

30

Fatal Serious Slight

Severity

No.

of A

ccid

ents

2000200120022003200420052006200720082009

Figure 2.2: Comparing accidents (2000-2004; 2005-2009)

Comparison of Accidents between period 2000-2004 and 2005-2009

8

31

96

12

28

107

05

101520253035404550556065707580859095

100105110115

Fatal Serious Slight

Severity

No.

of A

ccid

ents

2000-20042005-2009

2.3.4 Accident Conditions

The figures below offer a breakdown of total accident numbers across the scheme into the categories of Daylight/Darkness, Weather/Road Surface Conditions, Month, Day, and Time.


Figure 2.3: Accident numbers by Daylight/Darkness

Accident Numbe rs by Daylight/Darkness

112

33

2

0 20 40 60 80 100 120

Daylight

Darkness No Lights

Darkness Lights

Day

light

/Dar

knes

s

Accident Numbers

Daylight accidents on the A947 account for 76% of all accidents, whilst darkness accidents account for 24% (22% darkness no lights).

Figure 2.4: Accident numbers by Weather/Road Surface Condition

Accident Numbers by We ather/Road Surface Condition

53

83

7

2

2

0 10 20 30 40 50 60 70 80 90

Dry

Wet or dam p

Fros t or ice

Snow

Flood (m ore than 30m m )Wea

ther

/Roa

d S

urfa

ce C

ondi

tion

Accident Numbers

Accidents occurring during wet or damp conditions on the A947 account for 56% (flood conditions are a further 1%) of all accidents, whilst those occurring during dry conditions account for 36%. Accidents occurring during winter conditions (frost/ice/snow) amount to 6%.


Figure 2.5: Accidents by month

Accidents (% ) by Month

8.16

11.568.16

6.126.12

10.887.48

8.169.52

7.4811.56

4.76

0 2 4 6 8 10 12 14

January

February

March

April

May

June

July

August

September

October

November

December

Mon

th

Accidents (%)

Accidents are, according to these statistics shown above, most likely to occur in the months of February or November (June and September are also high). The least likely month for accidents to occur is December. The figures below indicate that the most frequent day for accidents to occur is Saturday (the least likely is Friday). The most frequent time for accidents to occur is between 1 and 2pm (7 to 8am is the second highest), and least likely between 1 and 3am.


Figure 2.6: Accidents by day of the week

Accidents (% ) by Day

16.33

14.97

14.97

14.97

8.84

19.05

10.88

0 5 10 15 20 25

Monday

Tuesday

Wednesday

Thursday

Friday

Saturday

Sunday

Day

Accidents (%)


Figure 2.7: Accidents by time of day

Accidents (% ) by Time

1.3600

1.363.4

6.126.12

7.484.76

2.046.8

4.766.8

8.846.12

3.45.44

4.764.08

6.124.76

2.040.68

2.72

0 1 2 3 4 5 6 7 8 9 10

123456789

1011121314151617181920212223

0

Hou

r of

Day

Accidents (%)

2.3.5 Accident Rates

In order to identify and prioritise schemes/remedial measures it is a commonly accepted procedure to represent accident numbers in terms of accident rates. For this report the approach used is as discussed and shown in Published Project Report PPR026 “Accident Analysis on Rural Roads – A Technical Guide” (TRL Limited, 2004). This approach includes the use of a national (UK) investigatory level (derived for rural ‘A’ class roads) for comparison. Concerns can therefore be highlighted where particular rates are above this investigatory level. The various accident rates have been calculated for the entire route length. Due to the dilution effect of the 61km scheme length the rates have also been derived for the four individual scheme sections. The accident rates are shown in the Table 2.12 below. Further, more widespread, analysis relating accident rates to specific factors has been carried out for each of the four specific scheme sections. These are shown on Tables 2.13 and 2.14 below. This analysis assists in the specific targeting of measures for each section.


Table 2.12 – A947 accident rates v. investigatory level, set 1


Table 2.13 - A947 accident rates v. investigatory level, set 2


Table 2.14 - A947 accident rates v. investigatory level, set 3


Although the overall accident rate for the route (21 accidents per 108 veh-kms), as shown in Table 2.12, is below the investigatory level (30) the rate for fatal accidents is almost 50% higher. More significantly, when the rates are considered per section it can be seen from Table 2.12 that Sections 3 and 4 provide worryingly high values. Section 3’s fatal accident rate is more than 200% higher than the investigatory level whereas Section 4 displays rates almost 50% higher for both overall (43 accidents per 108 veh-kms) and fatal accidents. The accident severity ratio is higher than the investigatory level in Sections 1 and 3 and it should also be considered that the overall accident severity ratio for the route (0.26) is marginally below the investigatory level of 0.27. To add further commentary to the A947’s negative performance against national trends, recent analysis carried out by Aberdeenshire Council has revealed that the accident rate on the route, between the three year period of 2008 to 2010, has increased to 23 accidents per 108 veh-kms. (Note: if this were calculated within the same boundaries as this particular route study (Parkhill to Banff, outwith urban areas) the rate may be 26 accidents per 108 veh-kms). What is evident from Tables 2.12 to 2.14 is that the primary safety concern across the entire length of the A947 route is bend-related accidents. On average, the accident rate relating to bends for the route is 243% above the investigatory level. Section 2 has a bend-related accident rate 433% higher than the investigatory level. Incidently the accident rate for bends has been calculated to be 12.57 bend accidents per 108 veh-kms. Other concerns of note are the high values over the investigatory level for accidents involving only one vehicle (114% above) and wet roads (45%; icy/snowy roads are also 30.3% above the investigatory level). These are, in many cases, related to each other and to inappropriate speeds. For accidents involving only one vehicle the top 4 recorded causation factors were loss of control (21%), slippery road (18%), travelling too fast for conditions (9%) and careless/reckless/in a hurry (5%). For accidents involving wet/icy/snowy conditions the top 4 recorded causation factors were loss of control (20%), slippery road (19%), travelling too fast for conditions (11%) and careless/reckless/in a hurry (6%).

2.3.6 Bend-Related Accidents

As is clearly evident from the above sections the most prominent concern is accidents related to bends. Of a total of 147 no. accidents over the five year review period, 71 accidents were bend-related ie. they occurred on or on the approach to a bend. 8% (4% of total) of these accidents were fatal, 20% (10% of total) were serious, and 72% (49% of total) slight. To put the factor of bends in full perspective the following should be considered:

• 50% of all fatal accidents occurred on bends • 50% of all serious accidents occurred on bends • 48% of all slight accidents occurred on bends

For bend-related accidents 76% were recorded as occurring during daylight and 69% of the accidents occurred during wet/damp weather or pavement conditions. Considering the scale of bend-related accident numbers a bend risk assessment has been produced for this report. The main aim of this is to ensure consistency of


signing and other remedial measures on the approaches to bends. This will be discussed later in the report. The results of the risk assessment are shown in Appendix B.

2.3.7 Junction-Related Accidents

As indicated previously DfT (2006) recommend the investigation of accidents related to junctions. Table 2.12 above shows, however, that junction-related accidents are not an immediate concern along the A947 with only 6 junction accidents per 100 junctions (the investigatory level is 14). Nevertheless a junction visibility survey was undertaken for the purposes of this study and the major junctions along the route have been assessed for their suitability, accident record, and existing turning provision. This is discussed later in the report.

2.3.8 Accident Causation/Contributory Factors

The collated information from the Stats 19 forms includes specific accident causation/contributory factors (up to 6 factors can be provided per accident) as determined by the Police. Analysis of this data has been carried out and allows the attainment of a greater understanding of the causes of accidents on this route. Below, figure 2.8 shows the primary (assuming that the first listed factor per accident is the primary cause) causation factors for accidents on the A947 route.


Figure 2.8: A947 Primary Accident Causation Factors

Primary Accident Causation Factors

3420

1211

1077

644

3333333

2111111111

0 5 10 15 20 25 30 35 40

Slippery road (due to weather)Loss of control

Failed to judge other person's path or speedFailed to look properly

Travelling too fast for conditionsFollowing too close

Careless/reckless/in a hurryExceeding speed limitImpairment by alcohol

Poor turn or manoeuvreAnimal or object in carriageway

Dazzling headlightsTyres illegal, defective or under inflated

Deposit on road (eg. oil, mud, chippings)Swerved

Sudden brakingInexperienced or learner driver/rider

OtherJunction overshoot

Poor or defective road surfaceFailed to signal/ Misleading signal

Defective steering or suspensionDisobeyed Give Way or Stop sign or markings

Pedestrian wearing dark clothing at nightFatigue

Disobeyed double white lineRoad layout (eg bend, hill, narrow carriageway)

Cau

satio

n F

acto

r

Number of Accidents

The accident analysis may be incomplete if the full range of factors (ie. causation factors 1 – 6 on Stats19 forms) were not assessed. Therefore figure 2.9 below shows the top 10 accident causation factors for the route (note – the top 10 factors make up 73% of the total factors).


Figure 2.9: A947 Top Ten Accident Causation Factors

A947 Top Ten Accident Causation Factors

3

4

4

5

5

6

7

8

13

18

0 5 10 15 20

Cau

satio

n Fa

ctor

s

%

Loss of Control

Slippery Road (due to weather)

Travelling too fast for conditions

Careless/reckless/in a hurry

Failed to judge other person'spath or speed

Failed to look properly

Inexperienced or learnerdriver/rider

Poor turn or manoeuvre

Sudden braking

Swerved

Table 2.15 below provides a breakdown of the top 20 causation factor combinations for the scheme.


Table 2.15 – A947 Top 20 Accident Causation Factor Combinations

To provide a further insight into causation factors, a study carried out by Devon County Council and Noble Denton Bomel (Noble Denton Bomel, 2009, “Devon Rural Road Project – Human Factors Rev.D”) introduced error classifications for the Stats 19 causation factors. For further information on the classification system the above report should be consulted, taking particular note of Table 2 within their Appendix A. The causation factors for the accidents over the review period on the A947 have therefore been categorised accordingly, as shown below.


Figure 2.10: A947 Accident Contributory Factors Classification

A947 Contributory Factors - Error Classification

18

2

24

47

3

1

3

1

0

0 10 20 30 40 50

Err

or C

lass

ifica

tion

%

Special Codes

Pedestrian Only

Vision Affected by (ExternalFactors)

Distraction

Unwitting Personal Impairment

Dangerous Error

Violation

Vehicle Defects

Road Environment Contributed

Likewise, the primary accident causation factors have been categorised into the error classification system as shown below.


Figure 2.11: A947 Accident Primary Contributory Factors Classification

A947 Primary Contributory Factors - Error Classification

29

3

22

39

3

0

2

1

1

0 10 20 30 40 50

Err

or C

lass

ifica

tion

%

Special Codes

Pedestrian Only

Vision Affected by (ExternalFactors)

Distraction

Unwitting Personal Impairment

Dangerous Error

Violation

Vehicle Defects

Road Environment Contributed

It should be noted that these results somewhat contradict the expected factor contribution for accidents as determined by RoSPA’s Rural Road Environment Policy Paper (2010). They highlighted that environmental factors (including road environment) are generally the prime cause in 2-3% of all accidents; that vehicle factors are the prime cause in 2-3% of all accidents; and that human factors are the prime cause for approximately 75%. As can be seen from Figure 2.11 above road environment factors contribute to a far higher percentage than may be expected (29%) and human errors account for 64% of the primary contributory factors.

2.3.9 Accident Factor Grids

For the purposes of clarity a general series of accident factor grids have been produced for each section of the scheme. These are located in Appendix A. Additional to this series of factor grids have also been produced for lighting conditions; weather conditions; pavement conditions; bend-related accidents; overtaking accidents; junction and non-junction related accidents; pedestrian-related accident; and child related accidents. These are located in Appendix A.

2.3.10 Urban Areas

Although outwith the remit of this study a brief review of the accidents within the urban areas of Newmachar, Oldmeldrum and Turriff revealed a very high accident rate within the boundaries of Turriff, as can be seen in the Table below.


Table 2.16 – A947 Urban Accident Rate

2.3.11 Problems with Incomplete Stats 19 Data

No ‘Damage Only’ statistics were received in relation to the A947. For a complete analysis and assessment it may be pertinent to include these. There is a fine line between damage only accidents and those resulting in casualties. Were Damage Only accidents to be included in any assessment it may also need to be considered that a large proportion of these accidents are not reported and may therefore not be in the statistics. Reported accident information is collated by a range of different personnel within both the Police and local roads authority. It is therefore possible that information may be misrepresented on site or ‘lost in translation’ when transferred to the local authority. Although, when considering the Stats19 1-6 causation factors for each accident, there is a high number of ‘unknown’ factors (527 out of 882, 59.75%) the number reduces dramatically when the first three factors are considered (133 out of 441, 30.15%). When taking the primary factor only into account there are 0 ‘unknown’ factors. A Road Safety Good Practice Guide (DfT, 2006) details some of the other issues with Stats19 data. These include: There is no specific definition of a bend or the severity of a bend The precise location provided for an accident can often be inaccurate. It may be beneficial for all local authorities (particularly neighbouring authorities eg. Aberdeenshire and City Councils) to have identical accident data available in order to maintain consistency and provide greater ease in comparing data.

2.4 Geometry of Existing Route

2.4.1 General

In order to assess the geometry of the existing route, the MXRoad software package in conjunction with the topographical survey were used to create both a horizontal and a vertical alignment by mirroring the existing road centreline. The topographical survey was undertaken by Becker Geomatics in September 2010 along the full length of the rural sections of the A947 (the corridor generally extended 10m outwith the existing road corridor). Geometric information could then be extracted by reporting on both of these alignments using MXRoad. The information attained from these reports included both horizontal and vertical parameters as well as the superelevation/crossfall and visibility (stopping sight and full overtaking sight distances) of the road throughout the assessed route length.


Upon completion of the initial information gathering exercise, individual geometric elements were then assessed. The MX reports for both the horizontal and vertical alignments were exported into excel spreadsheets and formatted in order to highlight specific geometric characteristics such as horizontal/vertical curve radii and lengths, gradients and vertical curve types. This information was then crosschecked against the relevant design standards, in this case Aberdeenshire Council Design Guidelines and TD9/93 of the Design Manual for Roads and Bridges (DMRB). However, in order to carry out this crosscheck, the appropriate design speeds for the route was first determined. Following an assessment of each individual parameter analysis was carried out to determine the compliance of the overall combined geometry with the relevant design standards.

2.4.2 Design Speed Assessment

A design speed assessment was carried out with the intention of determining the applicable design speed of the existing route. This was achieved by following Chapter 1 of TD9/93 of the DMRB and using the information acquired from the initial geometry assessment in addition to access and junction frequency, average carriageway and verge widths, and visibility. Both the alignment constraints (Ac) and layout constraints (Lc) specified in paragraphs 1.3 and 1.4 of chapter 1 of TD9/93 were calculated for the four sections of the route and from which the design speeds were then taken from Figure 1 of chapter 1 of TD9/93. For all four sections of the assessed route a design speed of 100Bkph was found. However, the design speed assessment carried out only takes into consideration the rural (national speed limit) extents; where existing speed limits are enforced the design speeds revert to their associated speed limit design speed e.g 40mph = 70kph (see table 2, TD9/93 DMRB).

2.4.3 Horizontal Alignment

Once the design speeds were established, a comparison of the existing horizontal radii and associated superelevation values against the relevant desirable minimum parameters within table 3 of TD9/93 was undertaken. It was noted that for a band B, all-purpose road, up to and including four steps below desirable minimum may be accepted as relaxations from standard (para 4.9 TD9/93) therefore any values below this may be classified as non-standard or departure from standard. Additional relaxation criteria as specified in paragraphs 4.10 – 4.17 of TD9/93 were also checked alongside the existing vertical alignment information which highlighted circumstances where relaxations could be extended or reduced. Table 2.17 below highlights the various horizontal design parameters and the allowable relaxations against the applicable design speeds/speed limits.


Table 2.17 - Minimum Horizontal Design Parameters Speed Limit National

Speed Limit 50 mph

40 mph

30 mph

20 mph

Design Speed 100 kph 80kph 70kph 60 kph 50 kph Min radius without elimination of adverse camber and transitions

2040 1440 1020 720 510

Min radius with superelevation of 2.5%

1440 1020 720 510 360

Min radius with superelevation of 3.5%

1020 720 510 360 255

Desirable min radius with superelevation of 5%

720 510 360 255 180

One step below desirable min radius with superelevation of 7%

510 360 255 180 127

Two steps below desirable min radius with superelevation of 7%

360 255 180 127 90

Three steps below desirable min radius with superelevation of 7%

255 180 127 90 N/A

Four steps below desirable min radius with superelevation of 7%

180 127 90 N/A N/A

The results of the full horizontal assessment were entered onto Excel Spreadsheets with the purpose of illustrating the various lengths of the route where the horizontal alignment either complies or does not comply with the design standards set out in Table 2.17 as well as each of the various relaxation steps below desirable minimum. The horizontal alignment assessment spreadsheets can be found in Appendix C. Vertical Alignment: A similar exercise to the above was undertaken for the vertical alignment by comparing the minimum hog and sag values in table 3 of TD9/93 against the values of the existing vertical alignment. It was noted that for a band B, all-purpose road, up to and including three steps below desirable minimum, may be accepted as relaxations from standard (para 4.9 TD9/93), therefore any values below this may be classified as non-standard or departure from standard. Table 2.18 below highlights the various vertical design parameters and the allowable relaxations against the applicable design speeds/speed limits. Table 2.18 - Minimum Vertical Design Parameters Speed Limit National

Speed Limit 50 mph

40 mph

30 mph

20 mph

Design Speed 100 kph 80kph 70kph 60 kph 50 kph Desirable min crest K value 100 55 30 17 10 One step below desirable min crest K value

55 30 17 10 6.5

Two steps below desirable min crest K value

30 17 10 6.5 N/A

Three steps below desirable min crest K value

17 10 6.5 N/A N/A

Absolute min Sag K value 26 20 20 13 9


An additional check on the desirable maximum and minimum vertical gradients was also carried out, using the maximum and minimum permissible gradients of 6% and 0.8% respectively, as specified in Aberdeenshire Council’s Standard for Road Construction Consent and Adoption, and the DMRB. Additional relaxation criteria as detailed in paragraphs 4.10 – 4.17 of TD9/93 were also checked alongside the existing vertical alignment information which highlighted circumstances where relaxations could be extended or reduced. As with the horizontal assessment, the results of the full vertical assessment were entered onto Excel spreadsheets with the purpose of illustrating the various lengths of the route where the vertical alignment either complies or does not comply with the design standards set out in Table 2.18 as well as each of the various relaxation steps below desirable minimum. The vertical assessment spreadsheets were separated into each section of the route and can be found in Appendix C. Visibility Assessment: The mainline visibility for the existing A947 was assessed using DMRB TD9/93 Highway Link Design. The standard states the desirable minimum Stopping Sight Distance (SSD) and Full Overtaking Sight Distances (FOSD) required for each design speed and the distances for steps below the desirable minimum visibility achieved. These distances (as shown in Table 3 of TD9/93) are shown in table 2.19 below. Table 2.19 - Visibility Distances Design Speed (KPH) 100 85 70 60 50 Stopping Sight Distance (m) Desirable Minimum 215 160 120 90 70 1 Step Below Desirable Minimum 160 120 90 70 - 2 Steps Below Desirable Minimum 120 90 70 - - 3 Steps Below Desirable Minimum 90 70 - - - 4 Steps Below Desirable Minimum 70 - - - - Not to Standard <70 <70 <70 <70 <70 Overtaking Sight Distances (m) Full Overtaking Sight Distance 580 490 410 345 290 Not to Standard <580 <490 <410 <345 <290 The visibility for the scheme was calculated using MXRoad Analysis of Through Visibility and was based on the topographical survey. Through visibility is used to assess visibility along a road using plan, profile and perspective views simultaneously. For each design speed with its associated stopping sight distance, SSD is measured from a driver’s eye height of 1.05m to an object height of 0.26m, whereas FOSD is measured from a driver’s eye height of 1.05m to an object height of 1.05m, both are checked in the horizontal and vertical plane in both directions. When the analysis is run, it will travel along the selected route to assess where visibility is lost, either as a result of changes in level (vertical) or bends (horizontal) in the road. Profiles are taken every 10m along the reference string using the specified


section offsets and this is displayed in a report showing the eye position, target position, eye level, target level and the resulting sight distance achieved. This process was used throughout the rural extents of the full scheme, taking into account the changes in speed limits throughout the 60km stretch, creating separate visibility reports for each speed limit. The results of these reports were then recorded onto excel spreadsheets (Appendix C) and are illustrated on the combined assessment drawings (P104898/02/01/100 – 109 in Appendix A). It should be noted that these visibility checks do not generally take account of overgrown vegetation. As the analysis is based on the topographical survey it only includes solid elements, e.g. wall/fence boundaries, trees etc. This aspect of visibility is considered under maintenance requirements.

2.4.4 Horizontal and Vertical Assessment

The findings from both the horizontal and vertical assessments were examined and a combined assessment was made highlighting the various lengths of the route where the pure geometry of the existing route either complies or does not comply with the design standards as well as each of the various relaxation steps below desirable minimum. Excel spreadsheets were created to document the results, which can be found in Appendix C.

2.4.5 Combined Assessment

A combined assessment of the existing horizontal and vertical alignments, stopping sight distances and full overtaking sight distances was undertaken with the purpose of showing the full geometric extent of the assessed route. The results of each individual assessment were drafted onto AutoCAD drawings in order to give a visual representation which clearly highlights areas of the route where the geometry is particularly poor and does not meet the required design standards. The combined assessment drawings (drawing numbers P104898/02/01/100 – 109) can be found in Appendix A.

2.5 Overall Description of Existing Route

Based on the assessment undertaken in the preceding sections, the following presents a summary of the overall geometry of the existing route. Section 1, Parkhill to Newmachar, Chainage 0 to Chainage 3280

This length of the A947 is generally a 6.5m wide single carriageway that runs from north of Parkhill to south of Newmachar, and is subject to a derestricted speed limit. There are 7 junctions present which are considered (junctions for single property accesses or shared accesses (up to and including 5 properties) are not considered) when assessing stopping sight distance and horizontal and vertical alignment. In terms of stopping sight distance and forward visibility, 70% of the route northbound and 81% of the route southbound achieve the desirable minimum distance. The remaining 30% and 29% respectively is a mixture of steps below standard and not to standard. The route has a limited number of


overtaking opportunities and this is amply demonstrated in the FOSD report produced for both directions of Section 1. Northbound shows two sections of 110m and 20m and southbound shows one section of 110m where FOSD is achieved. As this assessment covers 3.28Km, the frequency of overtaking sections is very low within section 1. The maximum gradient along the route is 2.073% which is within standard however there are numerous vertical curves that are below standard in accordance with DMRB TD9/93. The vertical curves not to standard make up approximately 20% of Section 1, therefore 80% of the vertical alignment is to standard or up to 3 steps below. Throughout the horizontal alignment approximately 30% of Section 1 is not to standard, with 70% of the section to standard or up to 4 steps below. From these statistics and as can be seen in drawings P104898/02/01/100 - 109 in Appendix A, the overall combined horizontal and vertical assessment for 40% of section 1 is not to standard. The sections of alignment which are not to standard appear intermittently throughout the section and are generally concurrent with SSD and FOSD that are also not to standard. For all four individual geometrical aspects of the assessment (horizontal alignment, vertical alignment, SSD and FOSD) an overall comparison was made for section 1. The comparison was based on acceptable combinations of relaxations as per TD9/93. This showed an overwhelming 100% of section 1 not to standard in the northbound direction and 99.4% not to standard in the southbound direction. This result is dominated by the FOSD results and therefore discounting FOSD from the assessment will give a much higher % of the scheme which complies to the design standards.

Section 2, Newmachar to Oldmeldrum, Chainage 4590 to Chainage 15455

This length of the A947 is generally a 6.75m wide single carriageway that runs from the north of Newmachar to the south of Oldmeldrum. It is subject to a combination of 50mph (1.4km long split in two sections) and a derestricted speed limit (9.465km long split in 3 sections). The 50mph sections occur at Whiterashes (Ch9050-9730) and Hattoncrook (Ch10250-10970) which are relatively small settlements. There are 18 junctions present which are considered (junctions for single property accesses or shared accesses (up to and including 5 properties) are not considered) when assessing stopping sight distance and horizontal and vertical alignment. In terms of stopping sight distance and forward visibility, 60% of the route both northbound and southbound achieves the desirable minimum distance. The remaining 40% is a mixture of steps below standard and not to standard. The route has a limited number of overtaking opportunities and this is amply demonstrated in the FOSD report produced for both directions of Section 2. The lengths of FOSD that are to standard are distributed intermittently throughout the section varying in length from 10m to 490m sections. The maximum gradient along the route is 5.395% which is within standard however there are numerous vertical curves that are below standard in accordance with DMRB TD9/93. The vertical curves not to standard make up approximately 29% of Section 2, therefore 71% of the vertical alignment is to standard or up to 3 steps below. Throughout the horizontal alignment approximately 4.5% of Section 2 is not to standard, with a very high


percentage of 95.5% of the section to standard or up to 4 steps below. From these statistics and as can be seen in the drawings P104898/02/01/100 - 109 in Appendix A, the overall combined horizontal and vertical assessment for section 2 is 47% not to standard. The sections of alignment which are not to standard appear intermittently throughout the section and are concurrent with the SSD and FOSD results that are not to standard. For all four individual geometrical aspects of the assessment (horizontal alignment, vertical alignment, SSD and FOSD) an overall comparison was made for section 2. The comparison was based on acceptable combinations of relaxations as per TD9/93. This showed 92.5% and 91.2% of the northbound and southbound lanes respectively as not to standard. This result is dominated by the FOSD results and therefore discounting FOSD from the assessment will give a much higher % of the scheme which complies to the design standards.

Section 3, Oldmeldrum to Turriff, Chainage 16760 to Chainage 40780

This length of the A947 is a 7.1m wide single carriageway that runs from the north of Oldmeldrum to the south of Turriff. It is subject to a combination of 30mph (0.24km long), 40mph (0.11km long), 50mph (1.14km long split in two sections) and a derestricted speed limit (22.53km long split in 3 sections). The 30mph section is a speed restriction on the south side of Turriff for traffic entering or leaving the town (Ch40540-40780). The 40mph section is a speed restriction on the north side of the town of Oldmeldrum for traffic entering or leaving the town (Ch16760-16870). The 50mph sections occur at Fyvie (Ch27510-28210) which is a small town with amenities and lots of housing, and Birkenhills (Ch36530-36970) which is a relatively small settlement. There are 36 junctions present which are considered (junctions for single property accesses or shared accesses (up to and including 5 properties) are not considered) when assessing stopping sight distance and horizontal and vertical alignment. In terms of stopping sight distance and forward visibility, 70% of the route northbound and 74% of the route southbound achieve the desirable minimum distance. The remaining 30% and 26% respectively is a mixture of steps below standard and not to standard. The route has a limited number of overtaking opportunities and this is amply demonstrated in the FOSD report produced for both directions of Section 3. Northbound has 5.04km of the total 24.02km to standard with southbound having 4.55km of the total to standard. The lengths of FOSD that are to standard are distributed intermittently throughout the section varying in length. The maximum gradient along the route is 5.287% which is within standard however there are numerous vertical curves that are below standard in accordance with DMRB TD9/93. The vertical curves not to standard make up approximately 13.1% of Section 3, therefore 86.9% of the vertical alignment is to standard or up to 3 steps below. Throughout the horizontal alignment 20.6% of Section 3 northbound and 22.9% southbound is not to standard, with 79.4% and 77.1% of the section is to standard or up to 4 steps below respectively. From these statistics and as can be seen in the drawings P104898/02/01/100 - 109 in Appendix A, the overall combined horizontal and vertical assessment for section 3 is 31.6% not to standard. The sections of alignment which are not to standard appear intermittently throughout the


section and are concurrent with the SSD and FOSD results that are not to standard. For all four individual geometrical aspects of the assessment (horizontal alignment, vertical alignment, SSD and FOSD) an overall comparison was made for section 3. The comparison was based on acceptable combinations of relaxations as per TD9/93. This showed 83.3% and 85.4% of the northbound and southbound lanes respectively as not to standard. This result is dominated by the FOSD results and therefore discounting FOSD from the assessment will give a much higher % of the scheme which complies to the design standards.

Section 4, Turriff to Banff, Chainage 42930 to Chainage 59350

This length of the A947 is generally a 6.9m wide single carriageway that runs from the north of Turriff to the south of Banff. It is subject to a combination of 20mph (0.35km long), 40mph (2.66km long split in two sections) and a derestricted speed limit (13.41km long split in 2 sections). The 20mph section is a speed restriction at King Edward Primary School (Ch51010-51360). The 40mph sections are both speed restrictions set in place for traffic entering or leaving the towns of Turriff and Banff, they occur at the north side of Turriff (Ch42930-43500) and the south side of Banff (Ch57260-59350). There are 32 junctions present which are considered (junctions for single property accesses or shared accesses (up to and including 5 properties) are not considered) when assessing stopping sight distance and horizontal and vertical alignment. In terms of stopping sight distance and forward visibility, 65.2% of the route northbound and 67.5% of the route southbound achieve the desirable minimum distance. The remaining 34.8% and 32.5% respectively is a mixture of steps below standard and not to standard. The route has a limited number of overtaking opportunities and this is amply demonstrated in the FOSD report produced for both directions of Section 4. The lengths of FOSD that are to standard are distributed intermittently throughout the section varying in length. The maximum gradient along the route is 5.683% which is within standard however there are numerous vertical curves that are below standard in accordance with DMRB TD9/93. The vertical curves not to standard make up approximately 17.2% of Section 4, therefore 82.8% of the vertical alignment is to standard or up to 3 steps below. Throughout the horizontal alignment 26.8% of Section 4 northbound and 28.1% southbound is not to standard, with 73.2% and 71.9% of the section is to standard or up to 4 steps below respectively. From these statistics and as can be seen in the drawings P104898/02/01/100 - 109 in Appendix A, the overall combined horizontal and vertical assessment for section 4 is 38.5% not to standard. The sections of alignment which are not to standard appear intermittently throughout the section and are concurrent with the SSD and FOSD results that are not to standard. For all four individual geometrical aspects of the assessment (horizontal alignment, vertical alignment, SSD and FOSD) an overall comparison was made for section 4. The comparison was based on acceptable combinations of relaxations as per TD9/93. This showed 88.3% and 88.2% of the


northbound and southbound lanes respectively as not to standard. This result is dominated by the FOSD results and therefore discounting FOSD from the assessment will give a much higher % of the scheme which complies to the design standards.

2.6 Bend Assessment

2.6.1 Background

As reported in the accident statistics it is clear that the primary safety concern across the entire length of the A947 route is bend-related accidents. The accident rate (12.57 bend accidents per 108 veh-kms) relating to bends for the route is generally well above the investigatory level. In fact, Section 2 has a bend-related accident rate 433% higher than the investigatory level. Noble Denton Bomel (2009) report that driver mental workload is higher on bends and that drivers have difficulties estimating the degree of risk involved in negotiating the bend. Following consultations with key stakeholders, in particular Aberdeenshire Council and Grampian Police, and several site visits there appears to be little or no consistency in the current provision for bend-related signage or road markings. As highlighted by TRL in 2005, psychological traffic calming (ie. non-physical measures eg. signage and road markings) can be effective in reducing accidents, via the reduction in vehicle speeds that are too fast for the prevailing conditions, if they are applied consistently and in a holistic manner. The Institute of Highways and Transportation guidelines (cited by RoSPA (2010)) also recommend that a consistent approach be taken to the signing and marking of bends on the same route such that the most severe are identifiable in the same way. Considering the scale of bend-related accident numbers and the apparent lack of current consistency of bend awareness a bend risk assessment has been produced for this report. The main aim of this is to ensure consistency of signing and other remedial measures on and on the approaches to bends.

2.6.2 Bend Assessment Calculation Sheet

The bend assessment calculation sheet has been formulated, in consultation with Aberdeenshire Council, using the Scottish Executive’s 2006 guidance ‘Hazard Warning Signs and Markings on Bends on Single Carriageway Trunk Roads’ as a starting point. The main aim is to assess and categorise bends such that common mitigation measures (as a minimum requirement) can then be easily applied. The Scottish Executive guidance was based on the assessment of the radii of the bends. Other available research reports that were utilised include TRL’s 2010 PPR494 ‘Bend Treatments on the A377 between Cowley and Bishops Tawton – final report’ and John Glennon’s 1998 report ‘Thoughts on a New Approach for Signing Roadway Curves’. These reports introduced the concepts of including superelevation, accidents and lateral friction demand in a bend assessment. These have all been incorporated into the assessment and a cumulative score is assigned to each bend which, in turn, allocates a category. This is shown within the Bend Assessment Guidance Notes (see Appendix B).


PPR494 specifically promotes the use of bend radii, superelevation and bend related collisions as factors in assigning risk scores to bends and subsequent categorisation. Consideration to risk score adjustment is also recommended on the basis of other potential sources of risk (eg. pavement condition, visibility, junctions etc.) prior to finalising the categorisation. As part of the partnering arrangement promoted in the undertaking of this route study, the bend assessment was discussed at length with Aberdeenshire Council. One important aspect that was considered was the factors to be used in the categorisation. It can be argued (as highlighted by TRL, 2010) that accidents should be included, but this can be countered by the permanence of such a factor (accidents can migrate, particularly with the introduction of remedial measures). On this basis both scenarios have been assessed within this report. The bend assessment calculation sheets for both scenarios can be seen in Appendix B. The results shown below and the drawings used to display the mitigation measures for each category are based on the ‘no accidents’ scenario. The drawings can be found in Appendix A. The bend assessment and categorisation should be undertaken as the first part of the assessment process. The bends and their respective categories should be reviewed alongside the results of the visibility assessment. It is suggested that the respective mitigation measures, be (at the very least) applied. Additional measures could be suggested in the case where visibility is very poor or where additional issues are identified. For all categories of bend the mitigation measures should be reviewed following specific individual site visits. This should be undertaken by experienced road safety engineers. Certainly some of the proposed mitigation measures may already be in place. Should this be the case the locations and condition of these should be assessed. The mitigation measures identified by the Bend Assessment should be further supported by educational and publicity campaigns to try and alter the behaviour of drivers with regard to negotiating bends.

2.6.3 Results

The assessments have been undertaken for the A947 route and the results are presented in Appendix B, alongside the Bend Assessment Guidance Notes. Southbound (60mph): Out of 186 bends originally identified from the topographical survey a total of 123 were categorised within the assessment. Of these 45% are category A, 36% category B, 19% category C, and 1% category D. Northbound (60mph): Out of 187 bends originally identified from the topographical survey a total of 124 were categorised within the assessment. Of these 45% are category A, 37% category B, 16% category C, and 2% category D. North/Southbound (40mph): Out of 17 bends originally identified from the topographical survey a total of 11 were categorised within the assessment. Of these 45% are category A, 36% category B, and 18% category C.


North/Southbound (30/50mph): For both the 30 and 50mph limit areas none of the bends identified in the topographical survey were categorised.

2.7 Existing Junction Layouts

On a rural route, such as the A947, junctions can often be obscured by bends, undulations or overgrown vegetation. RoSPA (2010) point out that conspicuity of the junctions is a key element in reducing junction related accidents. Advance warning signs and road markings, and regular maintenance of sightlines are essential mitigation measures on the approaches to and at junctions. As noted previously although junction-related accidents do not appear to be a specific issue on the A947 assessments have been carried out with regard to junction visibility and the provision and layout of major junctions.

2.7.1 Junction Visibility Assessment

The first stage in undertaking the survey was identifying all the existing junctions, leading to six or more properties or those with a large intake of commercial vehicles, along the route. This was done using the OS mapping in AutoCAD and the junctions, 77 in total, were highlighted for surveying. Survey Process The visibility at each junction was surveyed in accordance with TD 42/95 ‘Geometric Design of Major/Minor Priority Junctions’ which states that the visibility for a 100 kph design speed road should be 215 metres from the centre line of the minor road to the nearside edge of the main carriageway. The standard states that this should be achievable from 9m back along the centreline of the minor road, however in difficult circumstances this can be relaxed to 4.5m, and 2.4m in exceptional circumstances. The achievement of visibility is based on being able to see a marker 0.26m (target height) in height on the nearside edge of the main carriageway from a height of 1.05m (eye height) from the centre of the minor road. This represents being able to see a hazard from a seated position in a car. The survey was carried out at each junction for each set back ie 2.4m, 4.5m and 9m. One person stood at the junction with the 1.05m marker while the other person walked with the 0.26m, measuring the distance using the trundle wheel, until the 0.26m marker went out of sight. The distance at which the 0.26 marker went out of sight was recorded. See Appendix D for the results. If the minimum required distance was achieved at the first set back, the process was repeated for 4.5m and 9m respectively. Many junctions failed to meet the required distance (of 215m in most cases) at the 2.4m set back, therefore 4.5m and 9m also failed. Of the many junctions failing to meet the required visibility criteria, it was found that several were able to see the marker post although not being able to see the 0.26 m marker itself. In the majority of cases this was due to high verges or high vegetation in the verges. The lack of maintenance on the verges appears to be the primary cause of poor visibility on the A947. This has resulted, evidently, in high vegetation, overgrown trees and bushes and an overall restriction of sight.


In some circumstances the visibility was severely restricted due to being located on ‘blind’ corners or next to buildings or fences. Such examples of this include junction 39 at the Inverythan cottage and garage where the building and vegetation, as well as a public utilities pole, restrict the view to the South as shown in figure 2.12.

Figure 2.12: Junction visibility at Junction39

Another example of very poor junction visibility is demonstrated below in figure 2.13. This is the view to the South at junction 18a which is at Auchenhuive Cottages, just north of Hattoncrook, again heavily restricted by vegetation and fenceline. This junction however is also on a bend which increases the accident risk.

Figure 2.13: Junction Visibility at Junction 18a


Of the 99 no. junctions assessed, 14 were deemed to be fully acceptable and in accordance with the DMRB requirements for the associated speed limit; 33 were deemed acceptable in one direction; and 52 were deemed not to standard.

2.7.2 Major Junctions Assessment

The major junction assessment was undertaken by comparing the existing provision at major junctions against the requirements of DMRB TD42/95 (as directed by clause 18.15 of Aberdeenshire Council’s Transportation and Infrastructure Standards for Road Construction Consent and Adoption (Issue B). The “major junctions” were identified as those junctions between the A947 and any A or B class road. A total of 9 junctions were considered in the assessment and these are listed below: Table 2.20 – Major Junctions Assessment – Existing Provision Major Junction Existing Measures B979 to Blackburn Ghost island and taper B979 to Craigie Faded ghost island and

taper B993 to Inverurie Faded ghost Island and

taper A920 to Ellon No ghost island or taper B9170 to New Deer No ghost island or taper. B992 to Auchterless Ghost island and taper B9170 to New Deer Ghost island and taper B9105 to Fraserburgh Ghost island and taper B9026 to Macduff Ghost island and taper

2.8 Existing Pavement

2.8.1 Overview

As part of the overall assessment of the A947 the pavement condition information from Aberdeenshire Council was reviewed to give an overview of the likely maintenance requirements in the short to medium term. The two main sources of data were the "Sideway-force Coefficient Routine Investigation Machine" (SCRIM) Survey and the SCANNER "Scottish Road Maintenance Condition Survey" (SRMCS). The SCRIM survey and RCS data made available was only for one complete coverage of route. The RCS data was only made available as a summary and the individual component measurements were not made available. This summary deals with the assessment of the condition of the existing pavement, recommendations on treatment options, provisional costs, advantages, disadvantages and constraint of each option. This assessment did not take into account the existing traffic flows and limited construction records or previous maintenance works were made available in the compilation of this report. Therefore; no relationship between the structural properties and traffic loading can be established and no evaluation of the structural adequacy of the route can be considered.


The drawings and calculation sheets used in the assessment of the pavement can be found in Appendices A and E, respectively.

2.8.2 Scottish Road Maintenance Condition Survey

The SRMCS data is collected at close to normal road speed as part of the SCOTS agreement between all of the Scottish Councils. The SCANNER machines collect the following information:

(a) Ride quality, measured by 3m and 10m longitudinal profile variance, in the nearside wheel path. (b) Average rut depth in the nearside and offside wheel paths. (c) Average texture depth in the nearside wheel path. (d) Whole carriageway cracking intensity.

The collected information is then processed by the survey company in terms of Route Classification, for the particular indicators outlined above and there is a standardised series of factors applied for: Importance, Reliability and Weighting of each indicator, they are then summed and the percentage of the total calculated for each 10m section. The data is then evaluated in three categories:

(a) Total score less than 40 points designated as "GREEN" for lengths where the carriageway is generally in a good state of repair. (b) Where the total score is greater than 40 but less than 100 designated as "AMBER" for lengths where some deterioration is apparent which should be investigated further to determine the optimum time for planned maintenance treatment. The intervention may be determined based on the Roads Authorities internally determined serviceability levels, the repairs could be on the basis of minor repairs to delay the major expenditure on the basis of lowest whole life cost. (c) Sections where the total score is greater than 100 are designated as "RED" for lengths in poor overall condition which are likely to require planned maintenance imminently (probably within a year or so) on a "worst first" basis determined by the Roads Authorities Serviceability levels. Major repairs may be delayed by carrying out suitable repairs to maintain the road in a safe and serviceable condition on the basis of lowest whole life cost.

The summarised RCI data was provided on a series of six drawings from the 2008/2009 Survey, the bulk of the route was green where the carriageway was classified in a good state of repair as in (a) above. There are very short sections largely close to built up areas of Amber scattered along the route which are identified as having some deterioration and need further investigation in (b) above. There are a very small number of sections in the Red category which are identified as being in poor overall condition in (c) above, these are also largely close to built up areas. On the Northbound carriageway, from 2008/2009 results, approximately 73.9% of the whole length of the A947 route is classified as in a satisfactory state of repair, approximately 22.6% is in need for further maintenance and/or monitoring and approximately 3.5% requires maintenance treatment. On the Southbound carriageway approximately 76.1% is classified as in a satisfactory state of repair, approximately 20.5% is in need for further maintenance and/or monitoring and approximately 3.4% requires maintenance treatment. These results includes urban and MPI locations. The detailed results of this assessment can be found in Appendix E.


2.8.3 SCRIM Survey:

The Mean Summer SCRIM Coefficient (MSSC) survey data dated 2008, 2009 and 2010 was provided by Aberdeenshire Council on two series of drawings. The survey data collected was processed in accordance with the Design Manual for Roads and Bridges (DMRB) HD28/04 Volume 7 Section 3 Part 1, converted in Characteristic SCRIM Coefficient (CSC) values and compared with the predetermined Investigatory Levels (IL), in order to identify the lengths of road where skid resistance is at or below the IL. The route was assessed in accordance with HD28/04, Figure 2.1 and the Investigatory Levels assigned in accordance with table 4.1. It is believed that the SCRIM data received from the client was the result on only one survey pass in each year and therefore the value calculated by multiplying the measured Scrim Coefficient by the SFC to give the CSC. It is not known at what time of year the surveys were carried out so it is not possible to assess the data in the standard manner. There are a number of methods of programming out SCRIM surveys to ensure consistent data and to take account of the seasonal effects, on low traffic roads one approach is to carry out single annual surveys over a three year period and to ensure that the surveys are carried out in the early, middle and late times of the testing season, this enables trends to be identified. The traditional approach is to carry out two or three surveys per annum on sections of the network to enable the MSSC to be determined and used to assess other areas where fewer surveys are carried out. The data was reviewed on the basis that appropriate correction factors as above had been adopted in order adjust the collected datasets. The SCRIM values reported were quite variable with considerable lengths below the Investigatory Levels by varying amounts. The locations of the areas that were SCRIM deficient were plotted and compared with the accident and bend assessment data and this is shown in the drawings in Appendix A. The drawings show quite clearly where the SCRIM is deficient and may be a candidate for re-texturing or surface dressing but other information may be required as to the type and condition of the construction to determine whether the surface is suitable for either of these treatments. It has been noted on other projects that the SCRIM values after the initial period tend to deteriorate with age for traditional "Hot Rolled Asphalt" (HRA) surfaces but for "Thin Surface Course Systems" (TSCS) the SCRIM values can increase again slightly in later life as the material cracks. The SCRIM data was assessed in the following categories and is shown in detail in the table in Appendix E:

• Greater than or equal to 0.05 CSC units below IL - Treatment Required • Between 0 and 0.05 CSC units below IL - Investigate to determine if

treatment required • Between 0 and 0.05 CSC units above IL - Monitor to determine of treatment

required • Greater than 0.05 CSC units above the investigatory level - no action

currently required The information reviewed that there was considerable improvement in skid resistance along the A947 route between the two surveys and it is assumed that this was due to


a mixture of maintenance works and also the SCRIM surveys being undertaken at different times in the season but complete records were not available to confirm what treatments were carried out or the actual dates of the surveys and the corrections applied to the collected data. Results show that, in 2008/2009, both directions had approximately 6.1% is above the IL, approximately 40.8% is between 0 and 0.05 CSC below the IL and approximately 37.5% is greater than or equal to 0.05 CSC units below the predetermined IL. Approximately 15.6% of data was not considered due an urban region or an MPI location. However, in 2010 results, approximately 22.4% is above the IL, approximately 43.2% is between 0 and 0.05 CSC below the IL and approximately 19.2% is greater than or equal to 0.05 CSC units below the predetermined IL. Approximately 15.2% of data was not considered due an urban region or an MPI location. It may appear from the variability in the data sets that the 2008-9 survey may have been undertaken in the Autumn and the 2010 survey in the Spring and this with the maintenance works is the likely reason for the Improvement in the recorded values

2.9 Existing Road Drainage

2.9.1 General road drainage conditions

The existing provision of drainage was assessed using the British Standards such as HD33/06 and HA102/00. Drainage conditions were to be reviewed, in the first instance, from the accident statistics to identify locations where vehicles had skid in wet, snowy or icy conditions, or where surface water/flooding was noted. A full assessment of the drainage conditions along the full length of the route was not feasible due to budgetary and time constraints. Once specific locations were identified a site survey was undertaken on October 2010. It was found that on most cases the drainage provided was inadequate and in poor condition due to lack of maintenance. Gullies were found to be blocked or almost full of silt. At low points in the road only single gullies have been provided, which is not in accordance with HD102/00 or Aberdeenshire Council Guidelines (both of which require double gullies in this situation). The spacing of the gullies was also found to be below the standards; with the maximum required spacing should be 50m or a maximum area to be drained of 180m2. The road geometry in most cases was found to be below standard which resulted in some of the drainage problems such as ponding. High and low points at close proximity to each other, and with no gully provisions at low points is resulting in ponding of water and, in winter conditions icy road surfaces. Verge conditions along the A947 were found to lead to drainage problems with areas of ponding as a result of depressions in the verges from vehicle tracks. Edge of carriageways were found to be cracking and breaking up due to the settlement of the adjacent ground which has been caused by the lack of verge drainage and erosion from flows of water due to lack of gullies along the edge. Outfall locations along the A947 include a number of recognised water courses that run below or alongside the A947. There are also a number of smaller outfalls in the form of ditches that run alongside the route and ultimately lead to a watercourse.


2.9.2 Drainage Report on Specific Locations

As well as the general drainage conditions noted above specific locations where multiple accidents have occurred, with common contributory factors, were assessed providing the following results. Chainage 2575 (approx.) - a serious accident at the junction with B979. Potential drainage related causes: STATS19 form reported that the accident occurred when the road was wet. Existing gully provisions are below standard, are silted up and therefore require maintenance. Higher roadside verges could also lead to water flowing onto the road carriageway channels. Chainage 5500 to 6800 - a number of slight accidents. Potential drainage related causes: STATS19 form reported that the accident occurred when the road conditions were wet. The existing drainage provisions over this section of road was found to be sub-standard with gullies provided at non standard locations and high roadside verges. The overhanging tree canopy to the east verge at ch5800 and both verges at ch6600 in cold conditions, could also lead to icy road conditions due to the shelter provided from any sunshine. Chainage 7000 to 7500 - a number of accidents have occurred ranging from slight to fatal Potential drainage related causes: There provisions of gullies at this location meets the 50m spacing requirements however the drained area exceeds the 180m2 due to the gullies being provided on one side as the road is in crossfall. Ponding in the carriageway channel was found possibly due to localised dips along the channel. High overhanging trees on the northbound side could also lead to icy road conditions due to the shelter provided from any sunshine. Chainage 8320 approx – a slight accident occurred at the junction at this location. Drainage issues, no gullies are present within 100m in either direction of the junction. Potholes are evident on the northbound carriageway resulting in ponding in wet weather conditions. Chainage 11000 to 11650 - a number of accidents have occurred ranging from slight to serious. Potential drainage related causes: the drainage within this section consists of gullies which are silted up and below required standards of provision. High hedges within the verge alongside the south bound carriageway could lead to icy road conditions in winter months. Chainage 12200 (approx.) - a slight accident has occurred on this section of carriageway. Potential drainage related causes: a new ditch appears to have been recently provided for surface water runoff on the southbound carriageway but no provision has been made to convey the water from the surface to the new ditch, only a single gully near the carriageway high point has been provided, with a single gully at the low point (both in the southbound channel). Chainage 12650 to 13150 – a couple of slight and one serious accident has occurred. Potential drainage related causes: there are only two gullies provided over this 500m section of carriageway, both were fully silted up. Ponding in the south bound channel is evident which is possibly causing the visible erosion of the carriageway edge. The


verge throughout is at a higher level than the carriageway so any surface water is maintained in the channel. Chainage 13750 to 14000 - a couple of slight accidents has occurred on this section of carriageway. Potential drainage related causes: the high verges and lack of gully provision at the carriageway low spot could lead to ponding during wet conditions. High overhanging trees on both sides of the road in the winter season could lead to extended icy road conditions. Chainage 14200 to 14950 - a large number of accidents have occurred along this stretch of carriageway, with nine being classed as slight and one serious. Potential drainage related causes: the vertical geometry of the road has an unusual frequency of high and low points in sequence (undulating) with no gullies at the low points. This, in association with the high verges could lead to localised ponding of the channels. Erosion of the carriageway edges was also evident, possibly as a result of the lack of drainage provision. Chainage 21400 to 22400 - a number of accidents have occurred along this stretch of carriageway with two classed as slight, one serious and one fatality. Potential drainage related causes: There is a limited amount of gullies provided; only single gullies at the low points, that are silted up. This, in associated with the high verges could lead to ponding in wet conditions. The high overhanging tree canopy could lead to prolonged icy road conditions in winter. Chainage 25400 to 26200 - a number of slight and two serious accidents has occurred on this section of carriageway. Potential drainage related causes: Gullies located in the northbound channel were below standard and were all found to be blocked, which will cause the channel to flow with water in wet conditions. This coupled with a high tree canopy on both sides of the carriageway could cause icy road conditions in cold weather. Chainage 43700 and 44250 - a couple of slight accidents has occurred on this section of carriageway Potential drainage related causes: Gullies are below standard between and high verges are also present. The verges have partially covered over a kerbed section of the road and as a result grass is growing on the carriageway, The channel was also found to be eroded in places, and ponding was also evident within this section. Chainage 49700 to 50300 - a number of slight and one serious accident occurred on this section of carriageway Potential drainage related causes: there was surface water visible at the junction where the road geometry was relatively flat. No gullies are provided up or downstream of the junction. Gullies, provided away from the junction, were below standard but were found to be working with low levels of silt in them. A grass channel is present alongside the verge but the flow channel to it was blocked. Part of the carriageway has a large tree canopy which in cold weather may lead to icy road conditions. Chainage 50600 to 51000 - a few slight and a serous accident have been reported on this section of carriageway. Potential drainage related causes: only one gully was found at the carriageway low point. No other gullies on the north bound carriageway have been provided except opposite the junction access to Blackton Cottage (where three are present) with


ponding on the northbound lane evident between two of the gullies. The carriageway edge was also found to be cracking at this location. Chainage 51150 to 51500 - a couple of slight accidents has occurred on this section of carriageway. Potential drainage related causes: The gullies were found to be fully silted up, resulting in water flowing along the channels where erosion was evident in the carriageway channels and verges. There is also a high tree canopy along both side of the road, which in cold weather conditions could lead to icing of the road. Chainage 53800 to 54100 - a small number of slight accidents have been recorded on this section of carriageway. Potential drainage related causes: the gullies provided on both channels were blocked and therefore do not convey the water. Ditches have been provided at the back of the verges which have caused the surface water to erode the carriageway edge to a degree that the wearing course has fragmented and is loose. This, together with high vegetation and trees to both sides of the carriageway could lead to icy road conditions in cold weather. Note: At the time of the survey it was noticed that resurfacing works were due to commence on this stretch of road. Chainage 57700 to 58000 - a slight accident has occurred on this section of carriageway Potential drainage related causes: the existing gullies are alongside a high grass verge which was evidently being eroded with surface water flows. The remainder of this section of road was kerbed and in good condition. The gullies were in good condition, and the carriageway edge appears to have been recently repaired throughout.

2.10 Double White Line (Desktop) Survey

A complete double white line survey in accordance with Chapter 5 of the Traffic Signs Manual (TSM) may require a number of various activities over an extended period of time; a double white line review, a full consultation process with relevant authorities, an accident record analysis, and a site visit to verify previous findings. As part of this study it was agreed that due to time and budget constraints a site visit to complete the process may be undertaken at a later stage (during summertime). The design steps outlined in the TSM, Chapter 5, within paragraph 5.23, were generally followed in the assessment process. Firstly, the 85th percentile speeds were established in order to obtain the appropriate visibility distances. This was achieved by assessing the existing traffic speed information provided by four traffic counter locations, one in each of the route study sections. The calculated 85th percentile speeds along with their related visibility distances are shown below in table 2.21.


Table 2.21 – Visibility Distances (as per TSM Ch.5) 85th Percentile

Speed (mph) Desirable minimum

visibility distance V (m) Warning line visibility

distance W (m) Section 1 57.7 150 240 Section 2 57.7# 175 275 Section 3 67.1 175 275 Section 4 57.5* 175 275 # - Traffic counter located within 50mph zone therefore an 85th percentile speed of over 60mph has been assumed. * - Traffic counter data gives only average speeds at this location therefore an 85th percentile speed of over 60mph has been assumed. Secondly, the visibility of the existing route was then evaluated by using the topographical survey in conjunction with the visibility tools within MXRoad. The visibility outputs from MXRoad were then compared against the visibility distances within table 2.21, above. The subsequent design steps outlined in chapter 5.23 of the TSM, Chapter 5 were then followed and an AutoCAD drawing was created displaying the theoretical lengths of solid white line of the route. An assessment of the existing overtaking opportunities was then undertaken in order to establish the extent of the existing solid white line road markings. This was achieved by studying the video survey of the route and recording onto an AutoCAD drawing the type, length and location of all the existing road markings. Both the existing and proposed drawings could then be compared in order to establish the extent of additional solid white lines required throughout the full route. The extent of provision of existing carriageway centrelines can be seen in the drawings in Appendix A.

2.11 Existing Roadside Furniture

Another of the aims of the route study that may assist in accident reduction is the promotion of the A947 as a ‘self-explaining’ road. The Scottish Government (2005) highlight that one of the reasons often given by people for driving over the speed limit is that they were not aware of the speed limit. These roads seek to make the actions of road users more predictable through presenting the road clearly and unambiguously, offering few distractions and making drivers clearly aware of the layout of the road (including junctions and bends) and the speed that could be reasonably driven. RoSPA (2010) offer some advice on suitable measures that aid in promoting a self-explaining road. One of the concepts of self-explaining roads is ‘Forgiving Road Sides’, and the intention within the A947 route study is to promote Forgiving Road Sides where practicably reasonable. The theory of forgiving roadsides is the reduction of the numbers of and severities of accidents caused by vehicles leaving the carriageway, and hitting objects (eg. trees). The sections below therefore, taking into account ‘self-explaining’ roads and ‘forgiving road sides’, assess the current provision of the A947 with regard to roadside furniture.


2.11.1 Existing Signage and Road Markings

There are currently a large range of traffic signs on the A947, many of which are suitable for retention. There are, however, a number of signs that will require replacement or relocation with a number of additional signs required to be installed. The existing signs were surveyed using the video survey (from Streetwise) of the entire scheme, and transferred into AutoCAD format. These existing signs were then reviewed (against the requirements of the Traffic Signs Manual). The results of the assessment are shown on the Existing Road Furniture drawings in Appendix A. These drawings also include existing verge marker posts (note that these are considered further as part of the bend assessment process).

2.11.2 Existing Vehicle Restraint Systems

The existing vehicle restraint system locations were identified by using the video survey supplied by Streetwise, and distances and dimensions of barriers were determined using the topographical survey supplied by Beckers Geomatics. This information was then recorded onto an AutoCAD drawing, and an excel spreadsheet was also created scheduling the start and end chainages of all existing vehicle restraint systems, a breakdown of which is summarised by each section of the route below. The spreadsheet highlighting the existing locations of vehicle restraint systems can be found in Appendix G. Section 1 (Parkhill to Newmachar): Within section 1 of the assessed route there are existing vehicle restraint systems situated at one location for both northbound and southbound carriageways at ch.2700 where the hazard is an embankment greater than 6m in height. Section 2 (Newmachar to Oldmeldrum): At chainage 5080 on both the northbound and southbound carriageways, there are existing vehicle restraint systems in place in order to protect the road user from a watercourse hazard. Section 3 (Oldmeldrum to Turriff): Within Section 3 there are two locations on the northbound carriageway where existing vehicle restraint systems are in place; Chainages 22950 (embankment with watercourse), and 37990 (embankment with watercourse), respectively. On the southbound carriageway there are seven locations where existing vehicle restraint systems exist; Chainages 20250 (embankment greater than 6m in height), 20800 (embankment with adjacent road), 22940 (embankment with watercourse), 25550 (embankment with watercourse), 37980 (embankment with watercourse), 38400 (embankment with watercourse), and 38580 (embankment with watercourse), respectively. Section 4 (Turriff to Banff): There are three locations on the northbound carriageway within Section 4 where existing vehicle restraint systems are in place; Chainages 49670 (embankment with bridge and watercourse), 50950 (embankment with bridge and watercourse) and 58680 (embankment with houses) respectively. At chainage 50940 on the southbound carriageway there is an existing vehicle restraint system in place in order to protect road users from an embankment, a bridge parapet and a watercourse.


Assessment: An assessment of the existing vehicle restraint systems was then carried out using the requirements set out in TD19/06 of the Design Manual for Roads and Bridges (DMRB) and the criteria shown in the Aberdeenshire Council’s Standards for Road Construction Consent and Adoption in order to determine the required locations and lengths of all the existing vehicle restraint systems. The findings of this assessment indicate that all of the existing vehicle restraint systems adequately protect the road user from the relevant hazard.

2.12 Laybys

2.12.1 Existing Laybys

The locations of the existing lay-bys and slow moving lay-bys on the A947 were assessed using DMRB TD69/07, The Location and Layout of Lay-bys and Rest Areas. The standard states the criteria for the siting and frequency of lay-bys on single carriageways roads. Several factors are taken into account as the location of the lay-by could affect the safety of the lay-by and its intended use. A summary of the criteria used in assessing the location of lay-bys is in the table below: Table 2.22 – Lay-by Siting Criteria Siting Factors DMRB TD69/07 Lay-bys should not be sited on the inside of a left hand curve of radius less then the appropriate value for the design speed of the road.

Paragraph 3.2

Lay-bys should not be sited on the outside of a right hand curve with a radius less than the appropriate value for the design speed of the road.

Paragraph 3.3

Visibility on exit from lay-bys must conform to the requirements for a major/minor junction.

Paragraph 3.4

Drivers approaching a lay-by along the major road must be able to see vehicles entering or exiting the lay-by for a distance corresponding to the desirable minimum stopping sight distance in both directions for the design speed of the major road.

Paragraph 3.5

The separation between a lay-by and a junction or access, both upstream and downstream must be at least 3.75V metres where V is the design speed in km/hr.

Paragraph 3.7

Lay-bys must not be combined with a junction or access. Paragraph 3.8 Lay-bys should be sited on level ground and should not be sited on crests or gradients in excess of the desirable minimum value.

Paragraph 3.9

Lay-bys should be at least 150m apart and they should be staggered in a left-right configuration.

Paragraph 3.10

Lay-bys should be sited away from housing to avoid noise and visual intrusion and to reduce the possibility of trespass. For reasons of personal security, there should be an open aspect rather than woods or adjacent ground cover that might screen individuals from passing traffic.

Paragraph 3.11

When considering the frequency of lay-bys the recommended spacing as presented in Table 3-2 in TD69/07, and is also shown below.


Table 2.23 – Lay-by Recommended Spacing Carriageway Type Two-way Annual Average Daily

Traffic (AADT) Vehicle Flow Recommended Spacing

Single Carriageway >8000 2500 – 8000 1200 - 2500

Between 2km and 5km Between 5km and 8km Between 8km and 12km

The A947 currently has 12 existing lay-bys as shown below; two in section 2, six in section 3 and four in section 4. The lay-by assessment described was used to assess the current location of the lay-bys and their frequency within each section. The existing lay-bys are show on drawings in Appendix A. Table 2.24 – Existing Lay-bys

Section Lay-by No.

Type of Lay-by

Direction Side Chainage

2

1 Type A SB 5070.326

2 Type A with

Merge Taper Lay-by

NB 5492.711

3

4 Entrance to houses with

available parking. NB 19429.409

6 Type A SB 26051.971 8 Type A NB 28361.834

10 Type A but ties into another road. NB 34710.000

11 Type A but ties into another road. NB 35557.869

12 Type B SB 39554.515

4

13 Type A NB 42909.107 14 Type B SB 45526.395 16 Type A SB 56721.454 17 Type A SB 57942.598

2.12.2 Existing ‘Slow-Moving Vehicle’ Laybys

Slow-moving vehicle lay-bys are used to encourage slow moving vehicles, agricultural machinery, HGV’s etc., to pull in to allow convoys of traffic to pass. This ultimately reduces driver frustration in areas where there are limited over-taking opportunities. The A947 currently has 5 existing slow moving vehicle lay-bys, one in section 2, three in section 3 and one in section 4. The lay-by assessment described above was used to assess the current location of the slow moving vehicle lay-bys and their


frequency within each section. The table below shows a summary of the existing slow moving vehicle lay-bys. The existing slow moving vehicle lay-bys are show on drawings in Appendix A. Table 2.25 – Existing Slow Moving Vehicle Lay-bys

2.13 Existing NESCAMP Mobile Camera Sites

The existing mobile camera sites were identified by using the locations provided by NESCAMP and recording them onto an AutoCAD drawing. Therefore, the existing mobile camera site locations can be found on drawing number P104898/02/01/1800 – 1807 in Appendix A. There are currently 14 existing enforcement sites and they are generally located at existing lay-bys or within the carriageway verge. An assessment of the existing camera sites was undertaken in compliance with the guidance set out in the Scottish Safety Camera Programme Handbook. Due to the majority of the existing mobile sites being located in undesignated areas, it was decided that, wherever possible, the existing mobile sites be moved to a safer location, such as an existing or proposed lay-by where the appropriate visibility and conspicuity requirements are met. This was made possible following the lay-by

Section Lay-by No.

Type of Lay-by Direction Side Chainage

2 3

No Parking, Slow Moving

Vehicles Draw in to Permit Overtaking -

Type B

NB 12164.171

3

5



Type B

NB 24087.292

7



Type B

SB 26801.746

9



Type B

SB 31519.385

4 15



Type B

NB 48783.166


assessment, where existing and proposed lay-bys were identified throughout the route. Accident data was also used in the assessment in order to appropriately relocate or retain the existing mobile sites to areas where there is a history of road traffic accidents. Table 2.26 below shows all the existing mobile camera sites and their locations. Table 2.26 – Existing Mobile Camera Site Locations

Existing Mobile Site Ref.

Easting Northing Chainage Speed Limit

Description of Location

1 389094 816646 1+100 60 Northbound verge 2 387587 821003 5+825 60 Southbound verge 3 387647 820891 5+950 60 Southbound verge 4 385510 823460 9+325 50 Southbound verge 5 385173 823820 9+820 50 Northbound verge 6 380072 830653 19+525 60 Northbound verge 7 379519 832113 21+120 60 Northbound verge 8 378398 834398 23+670 60 Southbound lay-by 9 374608 844293 35+350 60 Southbound parking area 10 373690 848115 39+600 60 Southbound lay-by 11 373626 851171 43+950 60 Northbound verge 12 371529 857992 51+710 60 Southbound verge 13 371478 858674 52+400 60 Southbound verge 14 371574 862725 56+550 60 Southbound lay-by

2.14 Recorded Maintenance/Minor Works

Available records of recent maintenance/minor works along the route were provided by Aberdeenshire Council. They have been summarised and can be found in Appendix J. The records appear to have been kept but are inconsistent with each other. The information provided about the works and its subsequent usefulness to the route study is minimal.


3 PARKHILL

The Original A947 Route Study commenced at the proposed Aberdeen Western Peripheral Route (AWPR) tie-in south of the Goval Burn. In December 2010, the scope of the route study was extended in a southerly direction to the City Boundary (at the River Don). Through discussions with Aberdeenshire Council, it was deemed appropriate to include the section of the A947 further south based on the fact that there is currently a legal challenge against the AWPR which could delay the project by a number of years. On that basis an existing section of the A947 may remain in-situ, without the benefit of an in-depth road safety engineering review. The sections below will report directly on the existing conditions. Methodologies and background, unless specifically stated, will be as per Section 3 above.

3.1 Traffic Flow and Vehicle Speeds

3.1.1 Introduction

A brief capacity assessment for the junctions of the A947 & B977 just south of Parkhill has been undertaken to determine a requirement to upgrade the junction.

3.1.2 Base Traffic Surveys

After consulting Aberdeenshire Council no turning flow data could be provided for these junctions therefore data was taken from the AWPR Paramics Model (TS057). The flows taken from this report are for 2012 Do Something model and therefore may obviously have to be changed to fit the existing conditions for 2012 with no AWPR. In order to factor the flows from the AWPR Paramics Model the AADT’s for the Do Something and the Do Minimum were divided to give a factor for the difference in traffic volume and hence a difference to be applied to the flows. The AADT’s were taken from the AWPR Traffic Flows October 2007 Public Exhibition. From the Paramics Model the AM and PM peak hours have been identified as: AM Peak 08:00 – 09:00; and PM Peak 17:00 – 18:00. The peak hour traffic flows can be seen in Figure 3.1.


Figure 3.1 – 2012 Do Something AM and PM Peak Traffic Flows

Figure 3.2 – 2012 Do Minimum AM and PM Peak Traffic Flows


3.1.3 PICADY Capacity Assessment

PICADY 4 has been used to undertake a capacity assessment of the detailed design of the A947 / B977 junctions. The design RFC value of 0.85 (85% of theoretical capacity) is generally used as a threshold beyond which significant queues could form. ODTab input has been used for the AM and PM peak traffic flows in the models synthesized from a peak hour turning traffic count. The PICADY AM model shows an extremely large volume of queuing from Arm D (B977) turning left onto Arm A (A947 South), which can be expected due to the large volume of traffic making this turn with limited visibility. For the PM the biggest queues are again noted on Arm D however this time it is the right turn onto the A947 north that experiences queuing.

3.1.4 Conclusion

From the PICADY analysis of the geometry for the A947 / B977 junctions, they operate over capacity for year 2012 with significant build up of queues when applying the data above, this also reflects the existing site conditions.

3.2 Personal Injury Accident Data

In this section over the 5 year period only 3 accidents are recorded, 2 slight and 1 serious. Accident factor grids as for the other four sections detail the different accidents by using the STATS 19 data. It appears all three accidents happened in darkness although due to one of the accidents being assigned wrongly to Aberdeen City Council the data provided is not consistent with Aberdeenshire Council data and does not state the light conditions however it can be assumed darkness by observing the time and date of the accident. Table 3.1 - Parkhill Accident Numbers by Severity (2005-2009)

• Light Conditions – All 3 accidents happen in darkness as previously stated this is assumed for the Aberdeen City assigned accident due to time and date.

• Road Surface Condition – The road condition for the serious accident is dry, this is the same for 1 of the slight accidents. The remaining accident surface condition is unknown however it is snowing and therefore the road condition may be either wet or icy.

• Collision Factor – Two of the accidents have the same collision factor being “loss of control” with the final slight accident being “careless/reckless/in a hurry”.

The 2 “slight” accidents occur in relatively similar locations however are not related. One of the “slight” accidents also does not make impact with any other vehicle or any other object.

Accident Severity

No of Accidents

Slight 2 Serious 1

Fatal 0


3.3 Geometry of Existing Route

3.3.1 Geometry Assessment

A full geometry assessment was undertaken for the Parkhill area using the same method as described above in section 2. The results of each individual assessment and the combined geometry assessment can be found in the relevant spreadsheets in Appendix C and drawing number P104898/02/01/110 in Appendix A.

3.3.2 Geometry of Existing Route

Parkhill, Chainage 0 to Chainage 1550 This length of the A947 is generally a 7.3m wide single carriageway that runs from the north of Dyce to the south of Parkhill, and is subject to a derestricted speed limit. There are 3 junctions present which are considered (junctions for single property accesses or shared accesses (up to and including 5 properties) are not considered) when assessing stopping sight distance and horizontal and vertical alignment. In terms of stopping sight distance and forward visibility, 45.2% of the route northbound and 58.7% of the route southbound achieve the desirable minimum distance. The remaining 54.8% and 41.3% respectively is a mixture of steps below standard and not to standard. In both the northbound and southbound sections of Parkhill the route has no overtaking sections and this can be seen in the FOSD report produced for both directions of Parkhill and in drawing number P104898/02/01/110 in Appendix A. The maximum gradient along the route is 2.057% which is within standard however there are numerous vertical curves that are below standard in accordance with DMRB TD9/93. The vertical curves not to standard make up approximately 47% of Parkhill, therefore 53% of the vertical alignment is to standard or up to 3 steps below. Throughout the horizontal alignment approximately 40.5% of Parkhill is not to standard in the northbound direction and 46.3% is not to standard in the southbound direction, with 59.5% and 53.7% respectively of the section to standard or up to 4 steps below. From these statistics and as can be seen in drawing number P104898/02/01/110 in Appendix A, the overall combined horizontal and vertical assessment for Parkhill is 64.6% and 67.5% not to standard for the northbound and southbound directions. The sections of alignment which are not to standard appear intermittently throughout the section and are generally concurrent with SSD and FOSD that are also not to standard. For all four individual geometrical aspects of the assessment (horizontal alignment, vertical alignment, SSD and FOSD) an overall comparison was made for Parkhill. The comparison was based on acceptable combinations of relaxations as per TD9/93. This showed that 100% of the northbound and southbound lanes respectively as not to standard. This result is dominated by the FOSD results and therefore discounting FOSD from the assessment will give a much higher % of the scheme which complies to the design standards.

3.4 Bend Assessment

The assessments have been undertaken for the Parkhill section of A947 route, as per section 2.6 above, and the results are presented in Appendix B.


Southbound and Northbound (60mph): Out of 11 bends originally identified from the topographical survey 17% are category A, 42% category B, 33% category C, and 8% category D.

3.5 Existing Junction Layouts


The major junction assessment was undertaken by comparing the existing provision at major junctions against the requirements of DMRB TD42/95 (as directed by clause 18.15 of Aberdeenshire Council’s Transportation and Infrastructure Standards for Road Construction Consent and Adoption (Issue B). The “major junctions” were identified as those junctions between the A947 and any A or B class road. A total of 2 junctions were considered in the assessment and these are listed below: Table 3.2 - Major Junctions Assessment – Existing Provision Major Junction Existing Measures B977 to Balmedie Yellow box markings B977 to Kintore “Keep Clear” road

marking

3.6 Existing Pavement

The assessment of the existing pavement conditions within the Parkhill section has been undertaken as detailed in section 2.8 above. The results of the assessment discussed in section 2.8 are also applicable to Parkhill. The drawings and calculation sheets used in the assessment of the pavement can be found in Appendices A and E respectively.

3.7 Existing Road Drainage

3.7.1 General

Drainage was assessed using the British Standards such as HD33/06 and HA102/00. Drainage conditions were to be reviewed, in the first instance, from the accident statistics to identify locations where vehicles had skid in wet or icy conditions, or where surface water/flooding was noted. A full assessment of the drainage conditions along the full length of the route was not feasible due to budgetary and time constraints. Once specific locations were identified a site survey was undertaken in October 2010. From the site visit there is no visible drainage system in terms of filter drains and ditches, and no manhole covers were noted at this location. A single gully is located at the low point below the railway bridge in the northbound channel, with two further gullies noted; one in the southbound approach to the bridge approximately 30m from the bridge; and another again on the southbound carriageway at the junction of the B977 eastbound.


3.8 Double White Line Survey

A double white line assessment was undertaken as described in section 2.10 for the Parkhill section of the route. An 85th percentile speed of over 60mph was assumed, therefore the visibility distances of 175m (V) and 275m (W) were used in order to compare against the visibility reports produced by MXRoad. An assessment of the existing overtaking opportunities was then undertaken in order to establish the extent of the existing solid white line road markings. This was achieved by studying the video survey of the route and recording onto an AutoCAD drawing the type, length and location of all the existing road markings. It was found that there are no solid white centrelines throughout the entire Parkhill section and is delineated by either single centre lines or single warning lines therefore, overtaking could effectively be attempted throughout this section. Both the existing and proposed drawings could then be compared in order to establish the extent of solid white lines required. The extent of provision of existing carriageway centrelines can be seen in the drawings in Appendix A.

3.9 Existing Roadside Furniture

3.9.1 Existing Signage and Road Markings

A video survey of the route was undertaken. From this an assessment of existing signage and road markings can be made. This will include a double white line survey. All existing roadside facilities (bus-stops, laybys, footways etc) will be recorded from the video survey. Any maintenance issues will also be reported.

3.9.2 Existing Vehicle Restraint Systems

The existing vehicle restraint system locations were identified using the same method as described above in section 2. The assessment found that vehicle restraint systems are situated at one location within the Parkhill section for protection of both northbound and southbound road users from a watercourse/embankment/bridge parapet at the River Don (chainage 0 of Parkhill chainage system). An assessment of the existing vehicle restraint systems was carried out as described in paragraph 2.11. The findings of this assessment indicate that the existing vehicle restraint systems adequately protect the road user from the relevant hazard.

3.10 Lay-bys

3.10.1 Existing Lay-bys

There are two existing lay-bys within the Parkhill section of the A947, as shown below. These have been assessed as discussed above in section 2.12. The existing lay-bys are show on drawings in Appendix A.


Table 3.3 – Parkhill Existing Lay-bys

Section Lay-by No.

Type of

Lay-by

Direction Side Chainage

Parkhill X Type

B NB 1045.322

Y Type B SB 1419.367

3.10.2 Existing Slow Moving Vehicle Lay-bys

There are no existing slow moving vehicle lay-bys within the Parkhill section of the A947.

3.11 Existing NESCAMP Mobile Camera Sites

There are no existing mobile camera sites within the Parkhill section of the route.

3.12 Recorded Maintenance/Minor Works

Available records of recent maintenance/minor works along the route were provided by Aberdeenshire Council. They have been summarised and can be found in Appendix J. The records appear to have been kept but are inconsistent with each other. The information provided about the works and it’s subsequent usefulness to the route study is minimal.


4 MAJOR PROJECT INVESTIGATIONS

4.1 General

The initial scope of the project included for the preparation of a preliminary design for the following three historical major project investigation (MPI) schemes along the A947: Kingoodie realignment; Plaidy realignment; and Andrewsford Climbing Lane. Following an analysis of the accident statistics and accident factor grids for the route it was identified that these three locations may not necessarily reflect the best possible value for money. A brief assessment was therefore undertaken, taking into account clusters of accidents. RoSPA (2010) advise that in rural areas, accident prevention measures should be based on a comprehensive analysis of accident data of all accidents along the route in order to prioritise the areas with the worst accident records.

4.2 Assessment

Clusters of accidents were identified on the Accident Factor Grid drawings prepared for the route study. The identified areas were: Goval Burn Hattoncrook South of Oldmeldrum Andrewsford South of Turriff Plaidy Specific MPI accident factor grids have been prepared and can be location in Appendix A. An analysis of the accidents was undertaken in the same format as that for the route study, in order to highlight priority. Table 4.1 below shows the final results of the analysis (red indicates those not taken forward). Based on accident frequency, geometry and accident causation factors the following MPI ranking was agreed, in consultation with Aberdeenshire Council: Plaidy Goval Burn South of Turriff Andrewsford Hattoncrook South of Oldmeldrum* *South of Oldmeldrum was removed as a candidate MPI as route study remedial measures may be more appropriate to the accident causation factors and geometry. Plaidy MPI may be split into two areas (Auchmill to Lower Plaidy and Kinbate to Meikle Whiterashes) but considered as one scheme. South of Turriff may be considered from the town boundary to the layby at Brackin Braes.


In order to finalise the assessment and confirm the order of priority a high level cost benefit analysis was carried out. The results of which are shown below in Table 4.2. On this basis Plaidy, Goval Burn and South of Turriff, in respective order, may be progressed as MPI’s under this project. Andrewsford and Hattoncrook could be considered at a later stage for MPI’s. Preliminary designs have been prepared for the above three schemes and Preliminary Design Reports accordingly written.


Table 4.1 – Major Project Investigations Accident Analysis


Table 4.2 – Major Project Investigation Cost Benefit Analysis


5 THE 4 E’S

Of the 4 E’s, engineering and enforcement have been largely considered in the preceding sections. Noble Denton Bomel (2009) suggest that to ensure the effectiveness of engineering and enforcement schemes there also needs to be a fundamental shift in the behaviour of road users. In order to facilitate this the media of education and encouragement are used.

5.1.1 Education

Education plays a considerable role in the reduction of accidents; and does so in a proactive way, particularly by the specific targeting of potential and/or young drivers. This is vital considering the large numbers of young people involved in accidents on the A947. 28% of all accident involved vehicles (63 out of 223) were driven by people under the age of 25 – this comprised 20% male drivers and 8% female.

In order to promote road safety related education Road Safety Grampian has been recently established. In partnership with the local authorities of Aberdeen City, Aberdeenshire and Moray and Grampian Fire and Rescue Service, Grampian Police has a responsibility to reduce the number of collisions on Aberdeenshire’s roads, particularly those involving personal injury.

Under the umbrella of this partnership Grampian Police’s Road Safety Unit actively visits schools, colleges, universities and a substantial number of local businesses to deliver a wide spectrum of effective and innovative Road Safety presentations. This is done entirely free of charge.

One of the specific initiatives currently being promoted within Aberdeenshire is The Bus Stop! Campaign, that has been developed by the North East School Transport Safety Group, comprising Aberdeenshire Council, Aberdeen City Council, The Moray Council and Road Safety Grampian and has been supported by Talisman Energy (UK) and Stagecoach. In September 2008, two Aberdeenshire school pupils sadly lost their lives after getting off school transport, including one on the A947. Bus Stop! has been designed to help highlight the potential risks when getting off school transport and the dangers of distraction in this situation. It is hoped that Bus Stop! will continue to play an integral part of the approach to road safety education in schools and communities across the North East of Scotland. For further information on The Bus Stop ! campaign refer to www.1second1life.co.uk.

Another of the targeted vulnerable group within Aberdeenshire is motorcyclists. In 2010 Road Safety Grampian launched a new five year initiative, Operation Zenith. Operation Zenith involved partnership working between a number of different organisations and agencies including Road Safety Grampian, the association of motorcycle dealers for the North East of Scotland, Moray, Aberdeen and Aberdeenshire Councils, Bear (Scotland), the North East Safety Camera Partnership, Aberdeenshire Community Safety Partnership and Grampian Police (and now BP and Maersk). The first year has seen a 22% reduction in fatal and serious motorcycle collisions and over 4000 bikers being spoken to in the course of the year.

For further information on the road safety promotion initiatives and material used by Road Safety Grampian please refer to ‘A DESCRIPTION OF THE INPUTS DELIVERED TO YOUNG DRIVERS AND ADULTS BY ROAD SAFETY GRAMPIAN’ in Appendix K.

5.1.2 Encouragement

As discussed previously engineering, enforcement and education all contribute towards encouragement. To further encourage road users to adopt a more sensible approach on the road publicity campaigns, running concurrently to educational programmes, can be very effective. This


is because they address the root cause of the problem – the interaction between the road user and road layout or traffic situation. There have been many successful high profile road safety campaigns across the UK in the past (eg. drink driving), but often their effectiveness is immeasurable. Apart from education-related (listed above) or national road safety campaigns we are not aware of any specific encouragement campaigns along the A947. An excellent example of current Partnership working in road safety education is demonstrated by the ongoing hard-hitting local annual road safety show – ‘Safe Drive, Stay Alive’, that in recent years has been attended by all 5th Form Academy students within Aberdeenshire and Aberdeen City Council areas. In addressing the higher than desirable involvement of younger road users in the road traffic accidents reported within the A947 route study, there is considerable scope for the Partneship’s further proactive involvement in the reduction of such accidents on the A947, by directly involving those Academies that are served by the A947 within the scope of this study.


6 IDENTIFIED PROBLEMS AND PROPOSED INTERVENTIONS

6.1 Geometry

6.1.1 General

Six potential major project investigation (MPI) areas have already been identified within this report from which three preliminary designs have been undertaken. Taking into account the accident data (as shown on the accident factor grids in Appendix A) and using the geometry assessment drawings (P104898/02/01/100 – 109, Appendix A) it is possible to determine additional (to those previously identified) specific areas of the route which should be subject to further investigation. Table 6.1 below shows the areas of the route which are recommended for consideration for improvement works. It is recommended that site visits be undertaken by experienced road safety engineers to assess the desktop findings and determine appropriate remedial measures. Table 6.1 - Potential Areas of Improvement

Chainage Start Chainage End Total Length 6+350 7+800 1450m 17+300 18+120 820m 23+700 24+100 400m 28+450 29+800 1350m 38+300 39+000 600m 49+500 50+000 500m 50+150 50+600 450m 50+750 51+100 350m

6.1.2 Major Project Investigations

The three selected Major Project Investigations have been brought forward to preliminary design (see respective Preliminary Design Reports). It is recommended that two of the remaining candidate areas (Hattoncrook and Andrewsford) be considered for future upgrading works.

6.1.3 Parkhill

In the scenario that the AWPR scheme construction does not progress or is further delayed it is recommended that the A947-B977 junction be considered for a Major Project Investigation. Despite the low incidence of accidents on the A947 the poor geometry and junction layout, and significant queuing on the approaches to the junction there is a need for improvement works. This need will be even greater should the proposed park and ride site be progressed.

6.2 Bends

The results of the bend assessment assign categories to each of the bends along the route. It is recommended that in the first instance, as a minimum, the remedial measures shown below are applied to each categorised bend (for the calculations not including accidents). It should be noted that the assessment is carried out in both directions. From the assessment it can be seen that throughout the 60mph sections of carriageway there can be locations where the category is more severe in one direction. In these cases the mitigation measures applied should


be for the worst case category. An example of this is the bend between Ch. 46+461 to 46+516. In the northbound direction the bend has a category D whilst it is a category C southbound. The mitigation measures to be applied may therefore be for a category D bend. The bend assessment details drawings in Appendix A provide guidance on the application of these measures. On that basis, and on the premise that no measures are currently in place (or existing measures are inappropriate or deemed defunct), typical indicative costs have been calculated for the application of each suggested category as shown below. Table 6.2 – Bend Categories, associated Remedial Measures and Costs

Based on the costs shown in table 6.2 the total indicative cost for the application of mitigation measures on bends may be as follows: Table 6.3 – Total Indicative Cost of Bend Mitigation Measures

It is also recommended that the bend assessment process be completed by the undertaking of on-site evaluations of the bends to determine and/or confirm remedial measures applicability. The


bend assessment calculation sheet is not intended for use as a desktop substitute for the necessary site inspection.

6.3 Junctions

6.3.1 Junction Visibility

As reported above the majority of the junctions on the A947 are not to standard for their associated set speed limits. In many cases the visibility can be improved by increasing the frequency of verge maintenance and providing ‘clear zones’ adjacent to the carriageway. In other cases where visibility is reduced as a result of poor geometry and/or physical elements (eg. boundary walls) it is recommended that an on-site assessment be undertaken and specific measures identified where appropriate. It is unlikely, in most cases, that physical engineering works may be advantageous. Therefore all junctions should be either signed or junction marker posts should be used to improve the conspicuity of the junctions.


In light of the major junction assessment the following recommendations have been made, with an indicative cost of £320 (not including the potential for installation of a right turn filter lane and associated works at the A920 junction): Table 6.4 – Major Junctions Assessment – Recommendations Major Junction Existing Measures Proposed Measures B977 to Balmedie * Yellow box markings “Keep Clear” diagram

1026 road marking B977 to Kintore * “Keep Clear” road

marking -

B979 to Blackburn Ghost island and taper - B979 to Craigie Faded ghost island and

taper Road Markings to be renewed

B993 to Inverurie Faded ghost Island and taper

Road Markings to be renewed

A920 to Ellon No ghost island or taper Appropriate tapers and ghost island required. Detailed junction traffic assessment required to confirm need for tapers and ghost islands.

B9170 to New Deer Ghost island and taper - B992 to Auchterless Ghost island and taper - B9170 to New Deer Ghost island and taper - B9105 to Fraserburgh Ghost island and taper - B9026 to Macduff Ghost island and taper - * should these not be brought to MPI as per section 6.1.3 above The inclusion of continuous offset double white lining on all junction ghost islands and their immediate major road approaches along the route, minimising the dangers resulting from indiscriminate overtaking at these junctions, is recommended. Also attention should be given to


the number and spacing of forewarning arrows and centre hazard lines, to ensure they are in accordance with Chapter 5, Traffic Signs Manual (TSM).

6.4 Pavement

Based on the assessment of the SCRIM and SRMCS data the following recommendations are made:

• a review of the SCRIM surveys carried out to date, and the planning and methodology adopted be undertaken so that future surveys can be planned and adjusted on a rolling basis. This may enable the SCRIM values to be modelled in a suitable asset management system as a "functional condition" that deteriorates with time, traffic loadings and environmental conditions. This may enable the network manager to monitor trends in SCRIM over the network and to plan for the medium term the remedial measures required.

• all lengths where there is a SCRIM deficiency of 0.05 CSC units or greater be considered

for Surface Dressing or re-texturing with the considerations of surface construction type and condition as discussed above; a walk over survey may be sufficient to confirm the areas suitable for either of these treatments.

• all lengths where there is a SCRIM deficiency of 0 to 0.05 CSC units or greater be

investigated further to determine if and when they should be treated. This may require a walkover survey and ongoing review of the accident statistics.

• the section lengths where the SCRIM values are greater than 0.05 CSC units above the IL

require no treatment at present. The following points should also be given due consideration:

• Within the accident rates provided from 2005 to 2009, 74 of the accidents involved skidding due to wet and/or icy conditions. From 2008/2009 SCRIM test results it is evident that approximately 93% of accidents occurred where SCRIM had failed or was in poor condition and 49% of accidents occurred where SCRIM failed completely in accordance with HD28/04. However from 2010 SCRIM test results it is evident that approximately 82% of accidents occurred where SCRIM had failed or was in poor condition and 30% of accidents occurred where SCRIM failed completely in accordance with HD28/04. Although these results take into account all accidents from 2005 to 2009 it represents that SCRIM has improved over a three period. The more recent accident data since the skid resistance improvements were carried out in 2009 - 2010 may be required in order to assess the effect on the accident levels on the route.

• The efficient management of road networks can best be achieved with an effective

integrated asset management system that contains all of the road pavement and associated infrastructure and its base condition. This information in the case of road pavements may contain the construction information and the condition from various types of surveys and then deterioration models may be used to develop medium to long term maintenance plans.

• In order to carry out an effective assessment of the route for maintenance planning access

is required to the original Scanner data which may be stored on the Aberdeenshire Council Pavement Management System. If provided with these datasets for the recent years it may be possible to assess the rate of deterioration of the route and schedule up likely maintenance costs for the short, medium and longer term using systems such as RoSy


Asset Management Software. This software can handle all road pavement construction, testing datasets and also the other roadside infrastructure including lighting, drainage, structures etc. RoSy can then use this data with deterioration models and cost information to evaluate maintenance budgets and priorities over the required budget period and has an impressive track record in doing this around the world for over 300 clients. The value invested in this type of assessment can yield benefits as maintenance expenditure can be targeted at the areas with the lowest serviceability in terms of lowest whole life cost.

6.5 Drainage

6.5.1 General

The drainage on the A947 requires improvement throughout, with new gulley provision being highlighted as the main item required. New filter drains or trenches are also required in places. General maintenance of existing drainage items, with gullies and drainage pipes cleaned, any grass verges and channels vegetation cleared may improve the existing drainage along the A947. Additional items outwith drainage items may include improved verge and tree/shrub maintenance to reduce the shelter provided from any sunshine in colder weather. A general review of the gulley requirements has shown that an approximate 1,800 gullies are required for the whole scheme to be brought up to a minimum standard based on an average carriageway width of 7.3m and 180m2 of drained area per gully, resulting in a 25m gulley spacing to achieve this over the full scheme length. The topographical survey indicates that there are approximately five hundred and seventy existing gullies, the majority of which require maintenance.

6.5.2 Specific

The following specific recommendations are based on suitable outfalls being available and/or existing drainage being adequate for new drainage tie ins. Also, any upgrading may require a full drainage survey to be carried out to identify existing drainage apparatus, capacities, routes and outfall’s. Parkhill Chainage 320 (approx. – from Parkhill Chainage reference) An extra gully is required at the low point on the northbound channel to meet the current design standards. The existing drainage system will require to be traced to check condition, capacity and outfall. Indicative Cost - £270 (Gully only) Chainage 2575 (approx.) Six additional gullies may be required between Chainage 2450 and 2600 to bring it within the standards required. The existing drainage system will require to be cleaned and checked for capacity and outfall route. There is a watercourse at Chainage 2650 which the existing drainage possibly outfalls to and will this require to be assessed. Indicative Cost- £1,600 Chainage 5500 to 6800. Eight further gullies may be required to bring it within standard with four required between Chainage 5500 and 5850, four required between Chainage 6500 and 6800, with the gully tie in points required to be checked. The stretch of road between Chainage 5850 and 6500 has below standard spacing provision but no problems have been reported. To bring this stretch to standard


a further seventeen gullies may be required. Outfall locations are nearby and existing drainage may need to be traced and assessed. Indicative Cost- £6,700 Chainage 7000 to 7500 Due to the localised ponding in the carriageway channel, resurfacing works may be required to remove the localised dips to ensure a smooth gradient along the channel also ensuring that an adequate cross fall over the road is kept. An additional ten gullies are required to meet the current design standards. The existing gullies may be required to be cleaned and any associated filter drains and channels cleared of any silt and blockages. Indicative Cost- £2,700 (gullies only) Chainage 8320 (approx.) The potholes on the carriageway may be required to be repaired, and a potential new drainage system with gullies and filter drain system installed if there is no existing system present. This may comprise of one system from Chainage 8370 to an outfall to the north requiring 70m of filter trench and 30m of ditch at outfall, with 2 catchpits and 3 gullies. The other system may extend from chainage 8370 heading south to an existing drainage ditch at Chainage 8110 (approx) in the southbound verge, comprising of 200m of filter drain and 50m of ditch with 5 catchpits and 5 gullies. Indicative Cost- £20,500 Chainage 11000 to 11650 A further five gullies are required to meet the standard required for this stretch of road The existing network should be traced and the gullies cleared of silt. Where the road is in cut and there is runoff from the existing land the current provision of cut off drains and or ditches may require to be assessed and cleared where required. Indicative Cost- £1,350 Chainage 12200 (approx.). This small stretch of road may require a further three gullies to bring it up to standard including the additional gully at the low point in the road. The partially constructed filter trench in the southbound verge from Chainage 12050 to 12200 should be completed with a further three extra gullies to allow the surface water to enter the ditch. The outfall may require to be assessed. Indicative Cost- £1,950 Chainage 12650 to 13150 The drainage on this stretch of road should be investigated as there is a distance of 300m between gully positions; it is therefore unknown if any underground drainage items are present. On this basis, 400m of filter drain and seven catchpits together with ten gullies are required to meet drainage requirements. Indicative Cost- £14,000 Chainage 13750 to 14000 Three gullies and double gulley provision at the low point just south of the junction with Bourtie Lodge access are required in order to meet the standards. The existing below drainage should be investigated in order to check capacities and the outfall position. Indicative Cost- £1,350 Chainage 14200 to 14950 The stretch of road between Chainage 14600 and 14900 may require some resurfacing works to remove the localised dips to ensure a smooth gradient along the channel whilst also ensuring that


an adequate cross fall over the road is kept. An additional seven gullies may be required to meet standards. Indicative Cost- £2,800 Chainage 21400 to 22400 Approximately twenty two additional gullies are required to meet the standards on this stretch of road. The existing gullies require remedial works to the road surface surrounding the gratings. Indicative Cost- £5,900 Chainage 25400 to 26200 An additional fourteen gullies are required to be introduced to bring this stretch of road to the minimum requirement along this stretch of road. Indicative Cost- £7,400 Chainage 43700 and 44250 An additional nine gullies are required on this stretch of road to bring it up to standard requirements. The channel requires to be cleared of the silt/grass that have overgrown a kerbed section of the road Indicative Cost- £2,400 Chainage 49700 to 50300 A further twelve gullies are needed on this stretch of road to bring it the minimum standard required. The grass drainage ditch needs to be addressed; the flow from the road surface to the channel should be unblocked and cleared. Indicative Cost- £3,200 Chainage 50600 to 51000 An additional nine gullies are required on this stretch of road to bring it up to minimum standard requirements. The carriageway channel should be repaired to prevent ponding and further erosion of the verge. Indicative Cost- £5,100 Chainage 51150 to 51500 An additional nine gullies are required on this stretch of road to bring it up to minimum standard requirements. The existing gullies should be cleaned. The carriageway channel requires to be repaired to prevent ponding and further erosion of the verge Indicative Cost- £5,000 Chainage 53800 to 54100 An additional seven gullies are required on this stretch of road to bring it up to minimum standard requirements, with the existing gullies requiring to be cleared. Indicative Cost- £1,900 Chainage 57700 to 58000 An extra gully is required at the low point in this section and edge treatment (ie kerbing) to the carriageway edge to prevent erosion and further silting of the gullies is required between Chainage 57550 and 57830 on the northbound carriageway. Indicative Cost- £270 (gully only)


6.6 Double White Line Survey

Any proposed amendments to the existing provision of solid lines are based purely on the provision of any new lengths of or extensions to existing solid white lines.

As part of the informal partnering both Aberdeenshire Council and Grampian Police were consulted during the process. Following a review of the initial proposals, and in order to minimise driver frustration (generally in areas where there is significant non-overtaking), Grampian Police requested that the following areas of the assessment may be reconsidered. This was undertaken on a common sense approach, considering one step below sightline requirements.

The areas are:

1. Southbound adjacent to the Tarves junction at Auchenhuive.

2. Northbound to the south of Oldmeldrum (previously overtaking).

3. The junction at St.Katherines.

4. Immediately to the south of the permanent temporary speed limit at King Edward school.

5. Southbound at Ch. 48000 (approx.)

The reconsideration of proposals for these locations found the following:

1. Does not achieve one step below visibility requirements. Proposal to remain as Non-Overtaking

2. The proposed length of Non-Overtaking has been reduced by almost 300m

3. The proposed length of Non-Overtaking has been slightly reduced

4. The proposed length of Non-Overtaking has been removed

5. The proposed length of Non-Overtaking has been removed

Based on the proposed amendments the indicative cost of installation is £4,500.

Further details on the proposed lengths of solid lines, including for Parkhill, are provided in a spreadsheet in Appendix F. The results of this assessment can also be found in the drawings in Appendix A.

6.7 Lay-bys

6.7.1 General

TRL (2005) in a Scottish Executive report (Rural Road Safety: A Literature Review) commented on other research that suggested that, although rare, layby accidents tend to occur when the layby is situated on a bend or where drivers require to cross a carriageway to access a layby. The assessment of the existing laybys undertaken has therefore endeavoured to identify more suitable locations for all laybys.

6.7.2 Proposals

From the original 14 lay-bys (including the two at Parkhill) 8 are proposed to be retained (including one extension), 5 relocated to new sites (including one relocated to existing slow moving vehicle lay-by) and 1 new. The table below shows a summary of the existing lay-bys and the proposed lay-bys following the assessment. Appendix H contains the detailed assessment of the lay-bys. The proposed lay-bys are show on drawings in Appendix A.


The indicative cost for the proposals is £110,000 (approximately £20,000 for a new lay-by). Table 6.5 – Proposals for lay-bys

Section Lay-by No.

Type of Lay-by

Direction Side Chainage Status

2 1A Type B SB 8137.000 Relocate from

Lay-by No.1

2A Type B NB 5834.000 Relocate from Lay-by No.2

3 4

Entrance to houses with

available parking.

NB 19429.409 Retain

6A Type B SB 24950.000 Relocate

From Lay-by No.6

8 Type A NB 28361.834 Retain

9A Type B SB 31480.000

Relocate using

existing slow moving

lay-by No.9 10 Type A NB 34710.000 Retain

12A Type B SB 39592.000 Retain and Extend

4 13 Type A NB 42910.000 Retain

14A Type B SB 52102.000 Relocate from Lay-by No.14

18 Type B NB 52875.000 New Lay-by 16 Type A SB 56710.000 Retain

6.7.3 Proposals for Slow Moving Vehicle Lay-bys

From the original 5 slow moving vehicle lay-bys 3 have been retained (1 of which to be used as a conventional parking lay-by), 2 relocated and 1 new. The table below shows a summary of the existing and the proposed slow moving vehicle lay-bys following the assessment. Appendix H contains the detailed assessment of the slow moving vehicle lay-bys. The proposed slow moving vehicle lay-bys are show on drawings in Appendix A. The indicative cost for the proposals is £59,000 (approximately £20,000 for a new lay-by).


Table 6.6 – Proposed Slow Moving Vehicle Lay-bys

Section Lay-by No.

Type of Lay-by Direction Side Chainage Status

2 3


Vehicles Draw in to Permit

Overtaking - Type B

NB 12164.171 Retain

3

5A



Overtaking - Type B

NB 23405.000

Relocate from Slow

Moving Lay-by No.5

7



Overtaking - Type B

SB 26801.746 Retain

9



Overtaking - Type B

SB N/A

Retain as conventional lay-by (see proposed lay-bys)

4 19



Overtaking - Type B

SB 44700.000 New Slow

Moving vehicle lay-by

15A Type B NB 50575.000 Relocate

6.8 NESCAMP Mobile Camera Sites

6.8.1 Mobile Camera Site Assessment

Overall, whilst the data provided in the previous sections shows that inappropriate speed is a factor in a number of collisions, the actual collisions occurring where one of the vehicles is known to have been exceeding the speed limit for the road is significantly fewer. Nevertheless, consideration has been given to two types of fixed site speed cameras; the first being fixed site 'spot' speed cameras, and the second being fixed site 'average' speed cameras.


In terms of the potential benefit of fixed site 'spot' speed cameras, there are undoubtedly some straighter sections of the A947 where this type of camera may be practical, however those locations are not necessarily coincident with the collision clusters. Additionally, the A947 is a road heavily used by local traffic, resulting in camera locations becoming familiar to a higher number of drivers at an early stage. In consequence, the potential impact of the cameras, and ability to influence driver behaviour outside their immediate vicinity may be minimal. Fixed site 'average' speed cameras are generally considered to be very effective at moderating traffic speeds along a greater length of carriageway, and are also less susceptible to manipulation through local knowledge. However, again, where the evidence indicates the problem being one of inappropriate speed rather than excessive speed, their installation may be an expensive option, and one that may still not address the issue. In addition, the topography of the A947, with its frequent series of bends, and multiple entry and exit points along the entire length, may tend to support lower average speeds, and is therefore not best suited to speed detection based on time over distance methods. It is therefore recommended that the current policy of use of mobile speed cameras along the A947 be continued. TRL (2005) note the OECD’s findings that enforcement measures are effective in reducing accidents. It is vital, however, that the enforcement is both repeated and random (location) in nature in order to produce longer ‘halo’ effects. On this basis it is recommended that the proposed mobile camera sites, and associated signage, be introduced along the A947 and that they are enforced regularly and randomly.

6.8.2 Per Vehicle Record Data

On a similar route in Devon, the A361, PVR (Per Vehicle Record) counter data is being used to enable a more successful and specific targeting of speeding drivers. This counter data provides a recorded set of specific information for every vehicle that passes the counter that is set in the carriageway at specific points along the route. This information includes the date and time when the vehicle triggered the counter, type and length of the vehicle, as well as its speed and following distance (or distance behind the vehicle ahead). The counter is versatile in how it can analyse and present the results into meaningful output information. This information can indicate the speed limit at the specific site and the two-second following distance, as recommended by the Highway Code, as well as the number of vehicles exceeding the set speed limit. Analysis can be undertaken to identify the days and times of the week, for each location along the route, during which vehicles are driving most aggressively. This specifically aids the management and specific targeting of enforcement along the route. As reported in the A361 Road Safety Engineering Review, Devon County Council’s Partners – the emergency services, have found this material very helpful, particularly in the speed management of the A361. The counters can also be used to monitor the effectiveness of the interventions that are introduced along the route. Specific feedback was sought from Devon County Council with regard to the success of the counters. Appendix L contains a post-installation review of the effectiveness of the counters. The ‘Rural Road Safety Demonstration Project Progress Report’ also notes the success and effectiveness of the counters stating “enforcement partners have revised enforcement schedules to great effect, seeing an increase in the number of speeding prosecutions, particularly those relating to “top end” offenders. It has also proven invaluable in the evaluation of interventions targeting driver behaviour, painting a much clearer picture of how drivers react to their environment” (Aecom, 2009, p.9-10). Additional feedback reported that the counters cost £4,036 including installation and traffic management (for two counters). For real-time access to the data two decoders with the


associated GSM equipment were acquired at a cost of £1800 each. The annual GSM (telemetry) costs are approximately £120 per site. Throughout the route study consultation with both Grampian Police and NESCAMP revealed that they were both open to the application of such a system. It is therefore recommended that a pilot project be undertaken for the A947 including the installation of PVR counters along the A947 and assessment of data and identification of target areas (ideally on a fortnightly basis). Such a pilot project could be jointly funded by the roads and enforcing authorities. The indicative installation cost for the counters (including GSM access) may be approximately £45,800 (for 6 number sites – one in each of sections 1 and 2, and two in each of sections 3 and 4). Annual operating costs may be approximately £720. There may also be a cost associated with resources required to analyse the data.

6.8.3 Proposed Mobile Camera Site Locations

The existing mobile camera site locations have been reviewed. Following consultation with Aberdeenshire Council, Grampian Police and NESCAMP a range of proposals including new sites and the modification of existing lay-bys in order to accommodate a number of additional mobile safety camera sites have been made. The consultation included a site visit undertaken by Grampian Police and NESCAMP in order to review the proposed locations for suitability and enforceability. A total number of 18 mobile camera sites are proposed following Grampian Police and NESCAMP feedback. Of these, 8 existing sites may be retained, 6 may be removed and there are 10 proposed new sites. Table 6.7 below summarises all the proposals. For a more detailed account of the proposals see drawing number P104898/02/01/1800 – 1807 and the spreadsheet in Appendix I. The indicative cost for the installation of the additional locations is £77,500.


Table 6.7 – Proposed Mobile Camera Site Locations Mobile

Site Ref. Proposal Easting Northing Chainage Speed

Limit Description of Location

1 Retain 389094 816646 1+100 60 Northbound verge 2A New 387813 820682 5+550 60 Existing northbound lay-by 2 Remove 387587 821003 5+825 60 Southbound verge

3A New 387604 820945 5+890 60 Proposed northbound lay-by 3 Remove 387647 820891 5+950 60 Southbound verge 4 Retain 385510 823460 9+325 50 Southbound verge 5 Retain 385173 823820 9+820 50 Northbound verge

6a New 380080 830579 19+450 60 Existing northbound lay-by 6 Remove 380072 830653 19+525 60 Northbound verge 7 Retain 379519 832113 21+120 60 Northbound verge

8A New 378461 834189 23+460 60 Proposed northbound lay-by 8 Remove 378398 834398 23+670 60 Southbound lay-by

16 New 375941 837894 28+400 60 Existing northbound lay-by 19 New 375917 840790 31+430 60 Proposed southbound lay-by 9 Remove 374608 844293 35+350 60 Southbound parking area

9A New 374652 844542 35+590 60 Existing northbound lay-by 20 New 374690 846720 37+800 60 Existing bus stop 10 Retain 373690 848115 39+600 60 Southbound lay-by 11 Remove 373626 851171 43+950 60 Northbound verge 17 New 373855 851829 44+650 60 Existing southbound lay-by 12 Retain 371529 857992 51+710 60 Southbound verge

12A New 371517 858320 52+050 60 Proposed southbound lay-by 13 Retain 371478 858674 52+400 60 Southbound verge 14 Retain 371574 862725 56+550 60 Southbound lay-by

6.8.4 Proposed Signage

In reviewing the existing provision of mobile camera sites and their associated signage it was found that the signage needs to be upgraded to promote the scheme as a ‘self-explaining road’. Therefore the erection of associated ‘Gateway-type’ terminal and repeater signing providing a consistent message at regular intervals along the full route is recommended. These proposed signs have been reviewed and updated following comments by Aberdeenshire Council, Grampian Police and NESCAMP. The proposals can be found in the proposed road furniture drawings in Appendix A. The indicative cost for installation of new signs and relocation of existing signs is £39,350. Such interventions may form a timely reminder for road users to drive at a legally safe speed on a road that is regularly monitored by the Police. These measures may also help to maintain the level of consistency that is essential, particularly for those motorists that are driving the entire route, or are entering the A947 for the first time.

6.9 Roadside Furniture

To remain consistent with the holistic approach taken throughout the report, with specific regard to the A947 as a self-explaining road, the proposals detailed below shall all conform to the theory of


a ‘forgiving roadside’. 2m verges are proposed which may increase visibility, and all vehicle restraint systems, signposts etc shall be passively safe.

6.9.1 Signage and Road Markings

The proposed signs were assessed following the assessment of existing signs, in accordance with the Traffic Signs Manual. Additional sign requirements were identified, as were required sign relocations, replacements, and removals. The majority of the additional signs required were parking signs (as per diagram 801 in the traffic signs directions and regulations) to give advance warning of proposed laybys and junction ahead (as per diagrams 504.1, 506.1, 507.1, 512.1 and 512.2) warning signs. The Route Signage Proposals can be found on the Proposed Road Furniture drawings in Appendix A. The indicative cost of installation of all the proposed signs contained within the drawings along the scheme is £25,690. This is inclusive of the posts, sign faces and foundations. It may be possible to relocate or replace existing signs in some areas in order to reduce the cost. This cost assumes the use of standard steel posts however it is recommended that frangible safety posts be used on the scheme for improved safety. This may increase the cost. It should be noted that warning signs associated with bends are not included within the signage proposals; they have already been considered as mitigation measures as part of the bend assessment process. It is recommended that a review be undertaken of all existing directional signs in order to ensure that the concept of a self-explaining road is maintained. Following the assessment of the existing road markings, areas were identified where the markings were in poor condition. These areas are highlighted in the Proposed Road Furniture drawings in Appendix A. It is recommended that the identified markings are renewed at a cost of £2,500.

6.9.2 Vehicle Restraint Systems

Existing Systems

Although the findings of the assessment of existing vehicle restraint systems indicate that all of the existing vehicle restraint systems adequately protect the road user from the relevant hazard it is recommended that a site inspection of the existing vehicle restraint systems should be undertaken in order to determine the condition of each barrier and this should form the basis for any replacements. It should be noted that due to the length of the route, and the fact that it is not a trunk road, it was deemed inappropriate to use the Road Restraint Risk Assessment Process (RRRAP) (as per DMRB TD19/06), in the assessment process.

Proposed Systems

A separate assessment of the route was also undertaken in order to establish locations where additional vehicle restraint systems may be required as set out in TD19/06 of the DMRB and Aberdeenshire Council’s guidelines. A number of locations were identified and recorded onto an excel spreadsheet along with the start and end chainages, total length, the associated hazard and an indicative cost for each restraint system. This spreadsheet can be found in Appendix G, and is summarised below. All proposed systems are included in the Proposed Road Furniture drawings in Appendix A. The results for the separate assessment undertaken for Parkhill are also contained


on a spreadsheet which can be found in Appendix G. The proposed systems for Parkhill are included in the Parkhill Proposed Road Furniture drawings in Appendix A.

Parkhill: A total of three new vehicle restraint systems have been identified for the northbound carriageway within the Parkhill section, protecting the road user from hazards such as watercourses and bridges. A total of two new vehicle restraint systems have been identified for the southbound carriageway within the Parkhill section, protecting the road user from hazards such as watercourses and bridges. Indicative Cost £39,300.

Section 1 (Parkhill to Newmachar): No additional vehicle restraint systems required.

Section 2 (Newmachar to Oldmeldrum): A total of six new vehicle restraint systems have been identified for the northbound carriageway within section 2, protecting the road user from hazards such as watercourses and embankments with a height greater than 6m.

A total of four new vehicle restraint systems have been identified for the southbound carriageway within section 2, protecting the road user from various watercourse hazards. Indicative Cost £28,400

Section 3 (Oldmeldrum to Turriff): A total of six new vehicle restraint systems have been identified for the northbound carriageway within section 3, protecting the road user from hazards such as watercourses, embankments, bridge parapets and ponds. A total of ten new vehicle restraint systems have been identified for the southbound carriageway within section 3, protecting the road user from hazards such as watercourses, embankments and bridge parapets. Indicative Cost £124,900 Section 4 (Turriff to Banff): A total of four new vehicle restraint systems have been identified for the northbound carriageway within section 4, protecting the road user from hazards such as watercourses, embankments and bridge parapets. A total of six new vehicle restraint systems have been identified for the southbound carriageway within section 3, protecting the road user from hazards such as watercourses, embankments, bridge parapets and trees. Indicative Cost £41,200

General Recommendations

Additional hazards were also picked up such as telegraph poles, stone walls and trees but due to the frequency and length of some of these hazards, and therefore the cost of providing the vehicle restraint systems, it was decided that it may be reasonably practicable to omit them for the proposals. It is advised that accident data be monitored at locations where these hazards are


situated in order to assess the overall need. However, as a recommendation for the overall route, it may be more cost effective to relocate telegraph poles which are in close proximity to the carriageway rather than provide vehicle restraint systems at each location. Traditional barriers can have a negative aesthetic impact particularly in rural areas. Consideration should therefore be given to 2 innovative products that are promoted by Aecom (2009) – Primus 2a; and Nature Rail. Vehicle Restraint System, despite providing accident impact reduction for most vehicles, offer an increased risk for motorcyclists. Consideration should therefore be given to the installation of protective ‘skirts’ between the barrier and the ground.

6.9.3 Junction Marker Posts

It is recommended that Junction Marker Posts be installed throughout the scheme at all unsigned junctions. This may improve the conspicuity of vehicles leaving the junction and further promote the A947 as a self-explaining route. The proposed marker posts are included in the Proposed Road Furniture drawings in Appendix A. For cost purposes an Allegrini type post is proposed. Indicative Cost £750

6.10 Urban Areas

Although outwith the remit of this route study, reported accident statistics have recorded an accident rate of 89 accidents per 108 veh-kms on the A947 within the urban area of Turriff. It is therefore recommended that a safety review of the A947 section of road through the town be undertaken.

6.11 Maintenance

RoSpa (2010) discuss how poorly positioned roadside vegetation can cause severe injuries in the event of accidents occurring. They suggest the adaptation of a ‘clear zone’ within the verge – an area free of vegetation. The benefits provided may not only include a reduction in accident severity in the instance of an accident, but also increased visibility particularly at bend locations. The table below shows RoSpa’s suggested clear zone widths and associated accident reductions. Table 6.8 – Suggested Clear Zones and associated Accident Reductions

Noble Denton Bomel (2009) provide a commentary on the negative impacts on the readability of such a rural route due to a significant amount of hedges and trees lining the sides of the road. These impacts include:


• Vegetation can often obscure signs • Vegetation can create a ‘tunnel’ effect thereby forcing drivers to drive towards the centre of

the road • Taller overhanging trees can cause darkness and shadows thereby creating uncertainty

and visual confusion for drivers. As noted in the drainage assessment, in winter conditions they can also provide shelter and therefore extended icy/snowy conditions

It is therefore recommended that trees and hedges are cut back as far and as low as possible. Due to the issues highlighted with regard to visibility along the route it is also imperative that verge vegetation maintenance is prioritised on a regular basis throughout the year. It is also recommended that consideration be given to studying the appropriateness of applying roadside clear zones to the A947 (or sections of).

6.12 Partnering

One of the successes already widely acknowledged amongst the key stakeholders was the open consultation that was undertaken, that effectively enabled an informal partnership amongst the parties. It is therefore recommended that in the interest of road safety and general highway management (including records) on the A947, in the first instance, a formal partnering arrangement be founded. This may enable the successful review, prioritisation and implementation of the recommendations included within this report. Such an arrangement may also ensure that the knowledge gained and relationships built may be maintained. It may also provide a firm base for any future route studies; and it could be extended as part of an overall network management team. This may benefit all parties through the facilitation of knowledge/information transfer; the potential joint-funding arrangements for projects; highway maintenance; and accident remediation.

6.13 Highway Asset Management

One of the key findings of the data collection process was the poor quality and inconsistency of available information pertaining to asset management, particularly with regard to maintenance records. It is highly recommended that an all-in asset management database system be fully implemented and integrated within the entire Transportation and Infrastructure Service of Aberdeenshire Council. An all-in system, such as RoSy road system (the world’s most widespread software for asset management optimisation, see Appendix M for further information), can provide a highly efficient, accessible planning tool that encompasses a reliable, capacious and flexible road database; a maintenance planning module; a facility for implementing and administering digging within the highway network; pavement design; and a GIS facility.

6.14 Other Routes

A brief assessment of EuroRAP Risk Rating map (see Appendix N) was undertaken to evaluate the risks of Aberdeenshire’s A-class roads. Further to this, and on the basis of the A-class roads identified, consultation was undertaken with Aberdeenshire Council’s Road Safety Engineering Unit. The highest risk ‘A’ class roads within Aberdeenshire were confirmed to be the following:


A957 Stonehaven to Crathes 73 accidents per 100 million veh-kms A98 Fraserburgh to Fochabers 28 accidents per 100 million veh-kms A980 Banchory to Alford 27 accidents per 100 million veh-kms

The highest risk ‘B’ class roads within Aberdeenshire were also confirmed to be the following: B977 Kintore to Balmedie 40 accidents per 100 million veh-kms B9077 Glebe Cottages (A957) to Maryculter (B979) 32 accidents per 100 million veh-kms As noted earlier the accident rate for the A947 is currently at 23 accidents per 100 million veh-kms (calculated as 21 within this report). It should be noted that these accident rates are calculated from accident statistics between the period January 2008 to December 2010. The full list provided by Aberdeenshire Council is shown in Appendix N. It is therefore recommended that these ‘A’ class routes be the subject of comparable route studies, with a priority on the A957 and A98 routes. It is also recommended that, in the case of further delays to the procurement of the Aberdeen Western Peripheral Route, the B977 be the subject of a comparable route study.

6.15 The 4 E’s

Engineering and enforcement measures to facilitate the reduction of accidents on the A947 are outlined above.

6.15.1 Education

Current educational initiatives were earlier reviewed. These should all be continued and promoted. The various Road Safety Grampian initiatives should be actively extended to target the various academies located along and near to the A947 route, with the view to educating imminent young drivers that may be expected to drive the A947 over the coming years. PPR247 (TRL, 2006) highlights a growing trend in other parts of the UK of driver rehabilitation – the educating of road-related offenders. They list and review key strategies within ‘Tomorrow’s Roads – Safer Roads for Everyone’ to specifically target drink driving, drug driving and fatigue. Drink and drug driving are notably few within the accident factors on the A947 (4 and 0 respectively). Similarly fatigue was only recorded as a causation factor on one occasion. Nevertheless it is recommended that such strategies be continued within Aberdeenshire (it is noted that Road Safety Grampian currently run drink/drug driving campaigns, and that drink-driving rehabilitation schemes are sometimes offered to offenders). PPR247 also suggests that more emphasis should be placed on education and retraining, particularly in the case of low-end offenders, in lieu of gaining fixed penalty points.

6.15.2 Encouragement

As highlighted previously some of the key factors linked to accidents on the A947 are driving too fast for the conditions and bends. It is therefore recommended that a publicity campaign for the A947 be developed based on the campaign suggested by Noble Denton Bomel (2009) – ‘Are you around the Bend?!’, highlighting the perils of driving round rural bends. Another recommendation specific to the A947 is the adoption and installation of a series of road safety boards along the route. Such boards can include for example, as a stark reminder to drivers, the number of fatalities on the A947 in the last five years.


7 CONCLUSIONS

The A947 is a rural ‘A’ class road between Dyce, to the north-west of Aberdeen city, and Banff in Aberdeenshire. The route is approximately 61km in length and is generally orientated in a southeast-northwest direction and passes through the towns of Newmachar, Oldmeldrum and Turriff. This report highlights, through an extensive analysis of the Stats19 data, that over a five year period between 2005 and 2009 the A947 performs poorly in comparison with other comparable ‘A’ class roads in Aberdeenshire and in Scotland. The A947 is not meeting the Scottish Government set targets (for either 2010 or 2015/2020) for accident reduction. Comparing the detailed review period of 2005-2009 against 2000-2004 and against a three year period of 2008-2010 many of the accident rates are increasing. In comparison with a national Investigatory level the A947 accident rates in relation to bends are almost 250% higher, whilst those for fatal accidents are almost 50% higher. There is a considerably higher than average incidence where the accident causation factors are attributed to the road environment. The existing geometry, when assessed against the requirements of the DMRB, can be considered to be poor. This can, however, be attributed largely to the limited visibility (both SSD and FOSD) along the route. Major project investigations have been identified and preliminary designs undertaken (in separate reports) in order to improve three areas where the poor geometry is coexistent with a history of multiple and/or severe accidents. The condition of the existing pavement has been assessed by analysing the Road Maintenance Condition Survey (RMCS) and SCRIM surveys. The RMCS found that a little over 70% of the route is in a satisfactory condition. The SCRIM survey results displayed many locations where the pavement is considerably below the required investigatory levels. Two SCRIM surveys were consulted in the analysis and distortions were identified. This can be assumed to be as a result of a mixture of maintenance works or the surveys being undertaken at different times in the season. On that basis further assessment of the SCRIM surveys carried out should be undertaken and the planning and methodology of pavement assessment should be reviewed. The existing drainage provision along the route has not been fully assessed due to limited time constraints. Specific areas were identified where accidents were, at least in part, potentially caused by poor drainage conditions. It was generally found that there is an inadequate gully and verge drainage provision along the route. This report promotes and encourages the concepts, and application to the A947, of Forgiving Roadsides and Self-Explaining Roads. As part of this the need to standardise signs and road markings, vehicle restraint systems, and lay-bys, and the identification of features to facilitate both location and hazard awareness (in particular bends) has been addressed. A bend assessment procedure has been formulated and adopted for the route which assigns common safety and hazard awareness measures to bends on the basis of their severity. A desktop double white line survey was undertaken to review overtaking opportunities (or lack thereof) on the route, and additional slow moving vehicle lay-bys have been proposed to ease driver frustration in areas where there is limited overtaking opportunities. As one of the 4 E’s, enforcement measures have been identified as vital in seeking to reduce accident rates on the A947. Both Grampian Police and NESCAMP were consulted throughout the route study process. Existing mobile camera sites were reviewed and proposals introduced to ensure an optimal performance. As part of the concept of a self explaining route speed and safety


camera repeater signs are proposed with a view to encouraging and educating drivers to drive to more appropriate speeds. This is something that Road Safety Grampian are already actively promoting through their various road safety initiatives. As a typical rural ‘A’ class route road maintenance appears to be an issue on the A947. Limited sightlines across the verges, blocked gullies and verge drains, and poor pavement condition are all evident examples of this. It was also found that maintenance record keeping could be improved. There is, therefore, an important need for a robust maintenance and asset management process to ensure that the interventions that are implemented, and the existing provisions on the A947 remain effective in the future.


REFERENCES Aberdeenshire Council, 2008, “Transportation and Infrastructure Standards for Road Construction Consent and Adoption”, Issue B Aecom, 2009, “Rural Demonstration Project Report” Aecom, 2009, “A947 Route Analysis Primary Study” Design Manual for Roads and Bridges, Various Devon County Council - Road Safety Unit (Peter Gimber) DfT, 2006, “A Road Safety Good Practice Guide” Glennon, J, 1998, “Thoughts on a New Approach for Signing Roadway Curves” Noble Denton Bomel, 2009, “Devon Rural Road Project – Human Factors”, Revision D Peter Hellings Associates Limited, 2009, “Devon Country Mile project A361 Road Safety Engineering Review” Road Safety Grampian, 2010, “A DESCRIPTION OF THE INPUTS DELIVERED TO YOUNG DRIVERS AND ADULTS BY ROAD SAFETY GRAMPIAN” RoSPA, 2010, “Rural Road Environment Policy Paper” Scottish Executive, 2006, “Hazard Warning Signs and Markings on Bends on Single Carriageway Trunk Roads” Scottish Government, 2009, “Go Safe on Scotland's Roads It's Everyone's Responsibility” Scottish Government, 2009, “Reported Road Casualties Scotland 2008” Scottish Safety Camera Programme, 2008, “Handbook Scottish Safety Camera Programme”, Version 1.1 The Institute of Highways & Transportation, 1999, “Guidelines for Rural Safety Management” Traffic Signs Manual, Various TRL, 2004, PPR026 “Accident Analysis on Rural Roads – A Technical Guide” TRL, 2005, “Rural Road Safety: A Literature Review” TRL, 2006, “Review of Road Safety Good Practice in English Local Authorities” TRL, 2010, PPR494 “Bend Treatments on the A377 between Cowley and Bishops Tawton – final report” Also: http://www.grampian.police.uk/Advice.aspx?id=50&pid=30;34;16 www.1second1life.co.uk



APPENDIX A – DRAWINGS


APPENDIX B – BEND RISK ASSESSMENT


APPENDIX C - GEOMETRY ASSESSMENT SPREADSHEETS


APPENDIX D - JUNCTION VISIBILITY SURVEY


APPENDIX E – PAVEMENT ASSESSMENT


APPENDIX F – DOUBLE WHITE LINE SURVEY


APPENDIX G - VEHICLE RESTRAINT SYSTEMS ASSESSMENT


APPENDIX H – LAY-BYS ASSESSMENT


APPENDIX I - MOBILE CAMERA SITES ASSESSMENT


APPENDIX J – MAINTENANCE RECORDS


APPENDIX K - ‘A DESCRIPTION OF THE INPUTS DELIVERED TO YOUNG DRIVERS AND ADULTS BY ROAD SAFETY GRAMPIAN’


APPENDIX L - POST-INSTALLATION REVIEW OF THE EFFECTIVENESS OF THE PVR COUNTERS


APPENDIX M - ROSY ROAD SYSTEM


APPENDIX N - EURORAP RISK RATING MAP


APPENDIX O - WARD MEMBERS/COMMUNITY COUNCILLORS CONSULTATION

Documents

A947 Route Study Report - Final - Aberdeenshire Council€¦ · Route Study Report Prepared for: Aberdeenshire Council Transportation & Infrastructure Gordon House Blackhall Road