Ashford Joint Transportation Board · 1 To: Ashford Joint Transportation Board By: KCC Highways, Transportation & Waste Date: 13th June 2017 Subject: A2070/Barrey Road junction Classification:

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To: Ashford Joint Transportation Board

By: KCC Highways, Transportation & Waste

Date: 13th June 2017

Subject: A2070/Barrey Road junction

Classification: Information and Endorsement

Summary: This report updates the Board on progress relating to potential improvements at the A2070/Barrey Road junction and related actions as requested by the Board at its meeting held on 16th January 2017. It also seeks consideration and endorsement by the Board of the potential improvements to the junction and next steps.

1. Introduction

The actions requested by this Board at the January meeting are summarised as follows:

1.1 To Investigate the implementation of temporary speed restrictions and a

speed camera with further information on timescales, costs and an implementable scheme to be reported back to the group.

1.2 Early consultation with residents by Ashford Borough Council and Kent County Council to seek views about relocating the barrier in Church Road,

1.3 Highways England and Kent County Council be asked to progress the

further investigation of a longer-term solution of either a traffic signalised junction or roundabout at the junction of Barrey Road and the A2070.

2. Temporary speed restrictions 2.1 It was previously reported to this meeting that officers from KCC, HE and

the Safety Camera Partnership held initial discussions on the potential for introducing a temporary speed limit on the A2070.

2.2 Whilst information seemed to conclude that this may not happen before

the junction 10a works commenced, KCC are pleased to be able to report that there has been progress in this area and the introduction of a temporary speed limit of 40mph may be sooner than expected.

2.3 At the time of writing, a timescale is not yet available although it is hoped that the Board will be updated verbally at the meeting.

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2.4 Once installed, the impact will be monitored over 2 months to assess effectiveness on access to/from the Barrey Road junction from/to the A2070.

3. Relocation of the Church Road bollards 3.1 The informal consultation has been undertaken by KCC with assistance

from ABC and closed on the 28th April. Letters were delivered to approximately 109 properties asking for residents’ opinions on relocating the bollards either to a point near to number 64 Church Road (option 1), the Church Road/Barrey Road junction (option 2) or to leave the situation as it currently stands. There was also the opportunity for additional comments to be made and a specific email address was set up so residents could email their response if preferred.

3.2 21 forms were returned by post and 39 emails received. This equates to a

55% return and the summary results are shown in the table below:

Options % Number of replies

no choice indicated 6.67% 4

option 1 1.67% 1

option 2 23.33% 14

leave as current 68.33% 41

3.3 68% of residents who responded have stated their wish that the bollards should be left in the current location. Comments were also made that the only improvement that would make any real change in the area would be to address the Barrey Road/A2070 junction.

3.4 The main objections to relocating the bollards related to:

Narrow lanes with on street parking.

No footpath.

Concern that Church Road could become subject to increased parking.

Bridge at Church Road is not wide enough to take two way traffic and may not be suitable for potential HGV traffic.

Current congestion on Boys Hall Road would increase and is already at an unacceptable level.

HGV/delivery vehicle access along Sevington Lane and Church Road would be severely restricted

Potential issues for increased parking in Church Road and up to the Barrey Road junction

3.5 A summary of the comments made are attached in Appendix A

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4 Junction Improvements 4.1 Officers at KCC commissioned Consultants, WSP, to undertake an Options

Study of the Barrey Road/A2070 junction. The Brief was to identify options to improve access on to the A2070 and also to maintain the existing right turn in to Barrey Road from the southbound carriageway of the A2070.

4.2 Three options were identified in the Study, namely an acceleration

lane/nearside taper on to the A2070 from Barrey Road, a roundabout and partial signalisation, of which there were three sub options. A copy of the Options Study is attached as Appendix B and the summary of options considered are as follows: 1. An acceleration lane/nearside taper from Barrey Road on to the A2070 –

This was not considered to provide any benefits or improvement to the existing layout.

2. A new roundabout at the Barrey Road/A2070 junction - This would potentially involve additional land acquisition, diversion of utility plant and apparatus and potentially high costs to install.

3. Permanent traffic signals and partially signalisation of the junction – This

option has 3 potential variations, all contained within the highway boundary:

a) To signalise the existing junction arrangement b) As above but also to segregate the right turn in to Barrey Road

from the southbound A2070 c) In addition to point (b) above, provide signals on the southbound

A2070 and install a green signal head for through traffic. 4.3 The estimated construction costs only (project costs to include planning,

design, procurement, inflation etc. would be significantly higher) for the above can be summarised as follows: 1) Acceleration lane/nearside taper £300,000

2) Roundabout £450,000 3a) Signalise existing layout £175,000 3b) As (a) but with segregation £200,000 3c) As (b) but with additional signals £250,000

4.4 The WSP Options Study summarises and concludes that the provision of

partial signalisation addresses the aim to manage and create an appropriate gap for the entry/exit vehicles to/from Barrey Road above what is currently provided and on an option assessment score, provides a higher score than the other options of providing a nearside taper or roundabout control.

4.5 The part-signalisation option will also remove any conflict between Barrey Road and the A2070. In addition, the scheme has a positive Cost Benefit Ratio and delivers a positive annual benefit for the PM Peak improvements.

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4.6 It is the recommendation of the WSP Options Study that the junction of the

A2070 and Barrey Road is upgraded to a partially signalised junction in order to improve the access to Barrey road as per option 3c, shown on drawing number 9540-SK-006 in Appendix C of the Options Study Report.

4.7 As a result of the WSP recommendation, KCC commissioned an independent

cost review to capture the relevant elements pertaining to a scheme that would normally be included if the Highway Authority were delivering the scheme. The detail is shown in Appendix C and a summary of the anticipated minimum and maximum costs are shown in the table below:

Option Anticipated minimum cost Anticipated maximum cost

3a £477,000 £532,000

3b £521,000 £590,000

3c £613,000 £687,000

5.0 Next steps 5.1 The WSP Options Report and cost analysis have been shared with

colleagues at Highways England in order that they may undertake their own assessment of the results. Both parties will undertake to fine tune the estimated costs which will inform, advise and assist the further enquiries needed regarding any possible funding.

5.2 The cost review has been prepared on the basis of KCC undertaking any

improvement works, however, discussions with Highways England have focussed on exploring the potential for HE to undertake an approved scheme whilst the main junction 10a works are in progress. It is envisaged that there are both cost and time benefits to be realised by this approach.

5.3 It is anticipated that both the HE cost analysis and the funding enquiries

(which may also involve key Stakeholders) are undertaken as a matter of priority with a conclusion being reached by the end of September 2017.

6 Conclusion

6.1 The temporary speed limit is due to be introduced much sooner than expected and monitoring will be undertaken during its operation to assess the affect that it has on the entry/exit to and from Barrey Road.

6.2 The engagement with residents of Church Road, Nightingale Close and

Kingfisher Close has identified that the bollards should remain in their existing location

6.3 Further progress has been made in relation to the A2070/Barrey Road

junction with a suggested option brought forward for consideration and it is hoped that the Board will see this and the above as positive steps forward.

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7 Recommendations

7.1 It is recommended that the Board note the contents of the Report, the

progress to date and endorse the proposed approach detailed in item 5, taking forward the proposed partial signalisation (Option 3c) for further assessment and identification of potential funding streams.

Background documents:

Appendix A – Summary of residents’ comments relating to the Church Road bollards Appendix B – WSP Options Study Appendix C – KCC Cost assessment Contact officer: Andy Moreton – Kent County Council 03000 413423

Option 1 Option 2 Leave as current Commentsx Would result in increased traffic flow issues and Boys Hall Road junction was a concern

x Traffic lights at Barrey Road

x Reluctant choice but really wants to see lights at Barrey Road junction

x Useful to use Barrey Road, suggests lights or roundabout at Barrey Road or new road next to "Boots"

x Option 1 would not be a fair solution

x Makes most sense

x No footpath from No 12 and many parked cars beyond

x narrow roads. Either traffic lights or roundabout at Barrey Road

x traffic lights or roundabout at Barrey Road

x excellent idea

x Narrow lane, Church Road Willesborough already congested

x Seems most sensible solution

x narrow lane, hgv traffic over bridge, correspndence with HE regarding Barrey Road junction

x narrow lane, children play on the grass bank, slow the traffic on the A2070

no choice made narrow lane, made previous request for bollards to be removed which was declined, install traffic lights at Barrey Road

x Something needs to be done at the Barrey Road/A2070 junction, dangerous

x narrow lane a one lane over the bridge, no street lighting so pedestrians at risk with no footway focus should be on the Barrey Road/A2070 junction

x Provided bridge is strong enough to take weight of an oil tanker for deliveries.

x No additional comments

x No additional comments

x Option does not go far enough - traffic lights are needed at Barrey Road/A2070

x pursue the speed limit reduction on the A2070

x

x

x close of both ends of Church Road to prevent parking and ASB

x

x alternative route subject to parked cars, width limits and congestion

x KCC had advised many years ago that the bollards could not be relocated

x switch off J10 lights, install rbt at Barrey Road, Church road too narrow and congested

x alternative is heavily congested. Install signals at Barrey Road

no choice given requires a better solution to the problem

x reduce speed limit on A2070, slip road out of Barrey Road and improve lane designations

x superb idea, would be safer than using Barrey Road junction although congesiton at school times may be an issue

x no comments

x congestion on alternative route, double parked, school. Install rbt or signals at Barrey Road and enforce parking restrictions

x resident for 20 years and accepted that traffic would be an issue because of retail park

x have been advised that bridge will not take heavy vehicles - install lights or rbt at Barrey Road

x increased traffic on alternative route, narrow lanes, parked cars, no footpath, improve the Barrey Road junction

x increased traffic on church road and past school, other roads heavily congested, issue is with Barrey Road junction

x bridge weight limit, church road will become a car park, look at traffic lights option again

x congestion on narrow roads, weight limit on bridge, issue is with Barrey Road junction

x congestion on narrow roads, would cause more inconvenience, address Barrey Road junction and car park layout

x congestion on narrow roads, poor visibility on Boys Hall Road/Sevington lane, install lights at Barrey Road

x narrow lanes, poor visibility, bridge weight restriction?

x congestion on narrow roads, single lane traffic along church road, consider dedicated left hand lane in and out of Barrey Road

x poor access for delivery lorries, congested narrow lanes, dangerous junction at Boys Hall Road/Sevington lane

x long diversion, no real issues apart from righ turn in to Barrey Road - suggests roundabout or on slip to improve junction

x Church road not wide enough, children play on green at front, too much traffic for a small road - suggest rbt at Barrey Road/A2070

x alternative route detrimental, needs access to the A2070, church road/sevington lane far too narrow with parked cars.

x Church Rd/A292 congested, inconvenience to residents, issue remains at Barrey Road/A2070, congested, should petition for improvements

x congestion in Boys Hall Road/Sevington Lane, road unsuitable for increased traffic, need fundamental review in to Barrey Road/A2070

x longer, congested route to/from work, need lights at Barrey Road/A2070 with right turn facility

x roads not wide enough to take additonal traffic/deliveries. Dangerous bend, need to widen existing road. Provide new entry bo car park and extend Barrey Road across railway.

x longer journey time, congested roads, narrow lanes. Only solution is traffic lights or rbt at Barrey Road/A2070

x Fairest option for all residents

x Does not deal with the problem at Barrey Road/A2070. Pinch points on Church Road, increased parking

no choice made heavily congested through Willesborough, still need to access A2070. Install rbt at A2070 junction and yellow lines on Barrey Road for HGV's

no choice made single track road - neither options help the Barrey Road/A2070 junction - get developers to contribute to cost of works.

x personally option 2 is better but would require a closure also in place at T junction of Church Road to prevent parking/antisocial behaviour.

x congested roads, single track, no access for deliveries/HGV's. Does not resolve problem at Barrey Road.

REPORT NO 70029540-TN1

A2070 BAD MUNSTEREIFEL ROAD / BARREY ROAD OPTIONS STUDY

KENT COUNTY COUNCIL

MAY 2017

Type of document (version) Project no: 70029540 Date: May 2017

– WSP | Parsons Brinckerhoff Regus House George Curl Way Southampton Hampshire SO18 2RZ Tel: +44 (0) 2380 302529 www.wsp-pb.com

A2070 BAD MUNSTEREIFEL ROAD / BARREY ROAD

OPTIONS STUDY

Kent County Council

Q U A L I T Y M A N A G E M E N T

ISSUE/REVISION FIRST ISSUE REVISION 1 REVISION 2 REVISION 3

Remarks Draft for comment Final

Date May 2017 May 2017

Prepared by Wade Holmes Wade Holmes

Signature

Checked by Alex Thompson Simon Brownlie

Signature

Authorised by Alex Thompson Alex Thompson

Signature

Project number 70029540 70029540

Report number 70029540-TN1 70029540-TN1

File reference \\uk.wspgroup.com\central data\Projects\700295xx\70029540 - Barrey Road\02 WIP\DE Development\03 Document\03 Reports\20170504 - WH - TN1 Barrey Road.docx

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A2070 Bad Munstereifel Road / Barrey Road WSP | Parsons Brinckerhoff

Kent County Council Project No 70029540 May 2017

TABLE OF CONTENTS 1 INTRODUCTION ...........................................................................1

1.1 PREAMBLE .................................................................................................... 1

2 EXISTING CONDITIONS ..............................................................2

2.1 LOCAL FACILITIES........................................................................................ 2

2.2 NON-MOTORISED USERS............................................................................. 3

2.3 HIGHWAY NETWORK .................................................................................... 3

2.4 TRAFFIC VOLUMES ...................................................................................... 4

3 M20 J10A UPGRADE ...................................................................6

3.1 INTRODUCTION ............................................................................................. 6

3.2 EXTENT OF WORKS ...................................................................................... 6

3.3 FUTURE TRAFFIC FLOWS ............................................................................ 7

4 OPTION ASSESSMENT ...............................................................8

4.1 PREAMBLE .................................................................................................... 8

4.2 SITE CONSTRAINTS AND ASSUMPTIONS ................................................... 8

4.3 JUNCTION ASSESSMENT / DELAY .............................................................. 9

4.4 COST ESTIMATE ......................................................................................... 10

4.5 BENEFIT / COST RATIO .............................................................................. 10

4.6 OPTION ASSESSMENT SCORING .............................................................. 11

5 OPTION ASSESSMENT .............................................................12

5.1 INTRODUCTION ........................................................................................... 12

5.2 OPTION 1 - PROVISION OF NEARSIDE MERGING TAPER ........................ 12

5.3 OPTION 2 – ROUNDABOUT CONTROL ...................................................... 15

5.4 OPTION 3 – PART-SIGNALISATION............................................................ 19

5.5 COST ............................................................................................................ 21

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5.6 BENEFIT COST RATIO ................................................................................ 21

5.7 ASSESSMENT SCORE ................................................................................ 22

6 SUMMARY AND CONCLUSION ................................................23

6.1 SUMMARY ................................................................................................... 23

6.2 RECOMMENDED SCHEME .......................................................................... 23

T A B L E S

TABLE 4-1 - 2016 EXISTING JUNCTION LAYOUT ....................................................... 10 TABLE 4-2 - 2033 EXISTING JUNCTION LAYOUT ....................................................... 10 TABLE 5-1 – 2016 EXISTING JUNCTION LAYOUT WITH NEARSIDE MERGE TAPER13 TABLE 5-2 – 2033 EXISTING JUNCTION LAYOUT WITH NEARSIDE MERGE TAPER13 TABLE 5-3 - ASSESSMENT SCORE FOR NEARSIDE MERGE TAPER ....................... 14 TABLE 5-4 - 2016 ROUNDABOUT CONTROL .............................................................. 16 TABLE 5-5 - 2033 ROUNDABOUT CONTROL .............................................................. 16 TABLE 5-6 – BENEFIT COST RATIO OF ROUNDABOUT CONTROL .......................... 17 TABLE 5-7 - ASSESSMENT SCORE FOR ROUNDABOUT CONTROL ........................ 17 TABLE 5-8 – 2016 PART-SIGNALISATION................................................................... 20 TABLE 5-9 – 2033 PART-SIGNALISATION................................................................... 21 TABLE 5-10 – BENEFIT COST RATIO OF PART-SIGNALISATION .............................. 21 TABLE 5-11 - ASSESSMENT SCORE FOR PART-SIGNALISATION ............................ 22 TABLE 6-1 - SUMMARY ASSESSMENT SCORES FOR OPTIONS .............................. 23

F I G U R E S

FIGURE 1 - SITE LOCATION ..........................................................................................2 FIGURE 2 - 2016 OBSERVED TRAFFIC COUNT - AM PEAK (PCUS) ............................5 FIGURE 3 - 2016 OBSERVED TRAFFIC COUNT - PM PEAK (PCUS) ............................5 FIGURE 4 - M20 JUNCTION 10A WORKS (FROM HE PLANNING SUBMISSION) .........6 FIGURE 5 - 2033 FUTURE YEAR TRAFFIC COUNT – AM .............................................7 FIGURE 6 - 2033 FUTURE YEAR TRAFFIC COUNT - PM PEAK ...................................7

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A P P E N D I C E S

A P P E N D I X A NEARSIDE MERGE TAPER A P P E N D I X B ROUNDABOUT CONTROL A P P E N D I X C PART-SIGNALISATION CONTROL

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1 INTRODUCTION

1.1 PREAMBLE

1.1.1 WSP | Parsons Brinckerhoff have been appointed by Kent County Council to produce an Options Study report for a potential upgrade of the junction of A2070 Bad Munstereifel Road/Barrey Road, Ashford. This follows representations made by the residents and occupiers of the retail outlets/ business park located on Barrey Road to Kent County Council in relation to congestion at the junction. This congestion regularly leads to lengthy queuing and journey times for vehicles wishing to join the A2070 from Barrey Road.

1.1.2 The A2070 forms part of the Strategic Road Network and is managed and maintained by Highways England. Barrey Road forms part of the Local Road Network and serves a residential area and Ashford Business / Retail Park. Kent County Council has reported on receiving regular complaints concerning this junction with vehicles experiencing severe difficulty in joining the A2070 during peak periods.

1.1.3 Highways England is progressing works for significant improvements to Junction 10A of the M20 with the junction of A2070/Barrey Road falling within the red line development consent order boundary. This Options Study is intended to aide discussion between Kent County Council and Highways England to identify a suitable scheme for the Barrey Road junction.

1.1.4 The options proposed for the upgrade of the junction aim to manage and create an appropriate gap for the entry/exit for vehicles to/from Barrey Road above what is already provided under the existing priority controlled arrangement. Consideration is also given to the impact of the proposed scheme options with the mainline flows along the A2070.

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2 EXISTING CONDITIONS

2.1 LOCAL FACILITIES

2.1.1 The location of the junction of Barrey Road and A2070 Bad Munstereifel Road is contained in Figure 1.

Figure 1 - Site Location

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2.1.2 The Ashford Retail / Business Park contains approximately 50,000m2 of retail / light industrial

space. The retail park contains a mixture of warehouse retail, food and beverage outlets, and high street retailers.

2.1.3 Church Road, which leads-off from Barrey Road, is a residential area containing approximately 90 dwellings. The area is separated from the adjoining residential area of Willesborough by way of a road closure on Sevington Lane. All vehicles are therefore required to use the A2070/Barrey Road junction to access their properties.

2.2 NON-MOTORISED USERS

2.2.1 An elevated footbridge for pedestrian / cycle access extends over the A2070 from Church Road to Sevington and land east of the A2070.

2.2.2 Public Right of Way footpath AE339 is located along the northern side of Barrey Road linking Church Road to the A2070. This footpath crosses the A2070 at-grade at the junction. At the eastern side of A2070, the public footpath is obstructed by hedges and overgrown vegetation. The A2070 western side and Barrey Road southern side have a paved footway for pedestrians adjacent to the carriageway.

2.2.3 At the rear of the Ashford Business Park (south-western boundary), an elevated footbridge for pedestrian / cycle access extends over the South-Eastern Main Line railway to link the Ashford Retail / Business Park to Orbital Park and onto Ashford via Public Rights of Way footpath AE342 / AE343.

2.2.4 There is no provision for public transport in this location. The site is located adjacent to the South-Eastern Main Line railway, with the closest station at Ashford International located approximately 3km away.

2.3 HIGHWAY NETWORK

2.3.1 A2070 Bad Munstereifel Road is a dual carriageway comprising two vehicle lanes in each direction. The road is subject to the National Speed Limit of 70 mph for cars and motorbikes. The road links the A2042 at Ashford to the M20 at Junction 10. Street lighting is provided along the route. The road has No Stopping (Clearway) signs. No properties or developments front the road. Junctions along the road are evenly spaced, with a roundabout controlled junction provided at its junction with The Boulevard / Orbital Retail Park and a signalised gyratory provided at M20 Junction 10.

2.3.2 Barrey Road is a local road with a speed limit of 30mph. The road links the A2070 to retail and light industrial land uses and to Church Road residential properties. There is a weight restriction of 5T between 8pm – 7am. Although there are other minor roads off Barrey Road, the road is a no- through route. Street lighting is provided along the road. There are waiting and loading restrictions along some sections of Barrey Road controlled with double yellow lines.

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Photo 1 A2070 Bad Munstereifel Road/ Barrey Road looking north

2.3.3 The junction of Barrey Road and A2070 Bad Munstereifel Road (photo 1) is a priority controlled junction. The right turn from A2070 into Barrey Road has an offside diverging lane for the storage of right turning vehicles that is approximately 105 metres (or 18 vehicles assuming 5.75m per vehicle) in length. The left turn from A2070 into Barrey Road has no deceleration lane with vehicles being required to turn from the nearside traffic lane. The Barrey Road exit is configured to allow left turn movements only. The turning restriction is reinforced with traffic islands to physically prevent the prohibited movements. Any traffic wishing to travel southbound on A2070 is required to perform a u-turn at M20 Junction 10. There is street lighting provided at the junction. A2070 northbound approach has a downhill gradient approaching the junction.

2.3.4 A site inspection was carried out on 16th March 2017. At the time of the site inspection, line markings and signage were considered to be in adequate condition. Observations about the operation of the junction during the site inspection include:

A reluctance of vehicles on Barrey Road to enter A2070 when a vehicle was travelling on the A2070 offside lane, with many acceptable opportunities to enter the road network rejected by drivers;

The observation angle for vehicles emerging from Barrey Road is greater than 120 degrees due to the geometry of the channelised lane and the curved alignment of A2070, resulting in drivers observing oncoming vehicles over their shoulder; and

Gap acceptance times for vehicles turning right from A2070 into Barrey Road and for vehicles turning left from Barrey Road into A2070 was noted to be higher than typical urban situations, with many acceptable gaps being rejected by drivers.

2.3.5 A review of collision data for a 5 year period 2012 – 2016 has indicated that there were nine recorded collisions at the junction. All nine collisions were categorised as slight in relation to severity.

2.4 TRAFFIC VOLUMES

2.4.1 Traffic volumes have been sourced via previous investigations to assess the operational effectiveness of the A2070 / Barrey Road junction. These were undertaken by the consultants AECOM IN February 2017 on behalf of Highways England. Base year traffic counts were carried

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out on Thursday 15 December 2016 for the AM and PM peak period.

2.4.2 The AECOM report notes that the timing of the surveys precedes the Christmas trading period and is unlikely to be truly representative of typical conditions given the retail nature of Barrey Road. It is considered that using these traffic volumes provide a robust analysis of the typical junction operation.

2.4.3 Turning counts analysed by AECOM confirm that the junction experiences typical commuter peak hours of 08:00 – 09:00 and 17:00 – 18:00. A summary of the turning count data observed is shown in Figure 2 and Figure 3

FIGURE 2 - 2016 OBSERVED TRAFFIC COUNT - AM PEAK (PCUS) FIGURE 3 - 2016 OBSERVED TRAFFIC COUNT - PM PEAK (PCUS)

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3 M20 J10A UPGRADE

3.1 INTRODUCTION

3.1.1 Highways England announced in 2010 a proposal to construct a new Junction (10A) on the M20 approximately 700 metres south east of the existing Junction 10. The proposal includes a new elevated roundabout at the motorway junction and the construction of a new link road from Junction 10A to the A2070 Bad Munstereifel Road. An application for a Development Consent Order has been accepted and is currently under examination.

3.2 EXTENT OF WORKS

3.2.1 As part of the proposal, a roundabout will be constructed at the junction of A2070 Bad Munstereifel Road and the new link road. The proposed roundabout is approximately 200 metres north of the Barrey Road junction and north of the elevated footbridge. The provision of a roundabout will reduce the length of the route for Barrey Road traffic wishing to travel southbound along A2070, as the roundabout will cater for u-turn manoeuvres. The location of the proposed works is shown in Figure 4.

Figure 4 - M20 Junction 10A works (from HE planning submission)

3.2.2 As shown in Figure 4, the red line development consent order boundary for the J10A upgrade extends south of the proposed Junction 10A and includes the junction of A2070/Barrey Road.

3.2.3 The order of junction controls along the A2070 route will therefore include a mixture of priority controlled junctions, roundabouts and traffic signals, as illustrated in Diagram 1.

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Diagram 1 - A2070 existing junction controls

3.3 FUTURE TRAFFIC FLOWS

3.3.1 Future year traffic volumes for 2033 have been sourced via previous investigations to assess the operational effectiveness of the A2070 / Barrey Road junction carried out for Highways England by AECOM in February 2017. The 2033 future year traffic flows were extracted from the respective 2033 SATURN models used for the M20 junction 10a main assessment, with Barrey Road traffic volumes adjusted according to base year observations.

3.3.2 The future year traffic volumes see a significant increase in traffic flows along A2070. A summary of the future year turning counts is shown in Figure 5 and Figure 6.

3.3.3 It should be noted that the predicted traffic volumes for A2070 are considered to be high due to seasonal influences of the source data. Indeed, the flows may even exceed the theoretical capacity of the road, as well as the exit lane capacity of the proposed roundabout associated with M20 junction 10A. Nonetheless, the traffic volumes have been used in the assessment purposes to provide a robust analysis.

Figure 5 - 2033 Future Year Traffic Count – AM Figure 6 - 2033 Future Year Traffic Count - PM Peak

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4 OPTION ASSESSMENT

4.1 PREAMBLE

4.1.1 This report considers three options to upgrade the access at Barrey Road / A2070, which are:

Option 1 – Provision of a Nearside Merging Taper, with a sub-option providing a relocated pedestrian crossing of Barrey Road;

Option 2 – Roundabout control; and

Option 3 – Part-signalisation, with sub options providing for a splitter island to separate turning and through traffic, and one with additional signal heads.

4.1.2 The options have been assessed against criteria, detailed below, to determine which option should be recommended for further investigation. Each option will be considered in terms of the following:

Junction Delay

Cost

Cost Benefit Analysis and

4.1.3 Assessment scoring, which considers deliverability, integration with existing highway infrastructure, financial, access improvements, impacts on the A2070.

4.2 SITE CONSTRAINTS AND ASSUMPTIONS

4.2.1 The development of options for Barrey Road are subject to, but not limited to, the following site constraints and assumptions:

The elevated footbridge to the north has support structures which are within the highway boundary. The support structures will limit any widening of the carriageway or ancillary kerb works / footways.

The proposals for the upgrade of junction 10A will result in a new roundabout placed to the north of the elevated footbridge. All lane arrangements associated with changes at the junction of Barrey Road must be compatible with the lane configuration at the new roundabout.

The land to the north-west of the junction is identified as part of the Ashford Green Corridor Nature Reserve. Any widening of the carriageway on the western side will be contained within the designated highway boundary and should not encroach on the Reserve.

The proposals by Highways England for the upgrade of junction 10A will result in a speed limit reduction at the junction from 70mph to 40mph. As such, all designs have been assessed against standards for 70kph (approximately 40mph) in the Design Manual for Roads and Bridges.

The proposed roundabout to the north of the elevated footbridge will allow for all turning movements including u-turns. This will allow a route for vehicles out of Barrey Road to travel southbound along A2070 by first turning left out of Barrey Road and then u-turn and the new access road to junction 10A. As such, it is not a design requirement of the junction upgrade to provide a right turn out of Barrey Road onto the A2070.

The location of services and related infrastructure has been supplied by Kent County Council. No detailed service inspection has been undertaken. The services information provided

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indicates that the majority of services are running north /south parallel to A2070 on its western side. Nevertheless proposed designs will aim to minimise likelihood of impact on existing services plant.

4.3 JUNCTION ASSESSMENT / DELAY

4.3.1 Junction assessments have been carried out using the modelling programs Junctions 8 and LinSig. These programs provide an assessment of the impact on traffic capacity, queues and delays at a junction. Junctions 8 developed by Transport Research Laboratory, is used to assess priority junctions and roundabouts. LinSig developed by JCT Consultancy is used for traffic signal junction analysis.

4.3.2 The results of the roundabout and priority junction assessments are expressed in terms of the predicted Ratio of Flow to Capacity (RFC) for each arm of the junction. The RFC provides a numerical indication of the likely performance of a junction. Volume 6 Section 2 of the Design Manual for Roads and Bridges contains the document TA23/81 ‘Junctions and Accesses: Determination of Size of Roundabouts and Major/Minor Priority Junctions’, which provides advice on the interpretation of RFC values. The document states that if any arm has an RFC ratio of 85% (0.85), queuing will theoretically be avoided in five out of six cases. Therefore an RFC below 0.85 is regarded as demonstrating that the junction will work satisfactorily with minimal delay to vehicular traffic. RFC values over 1.0 indicate that the junction is over design capacity with significant delays being likely on at least one arm of the junction.

4.3.3 LinSig models provide an indication of the Degree of Saturation (DoS), Mean Maximum Queue (MMQ), the average delay per vehicle on each approach and the Practical Reserve Capacity (PRC). For DoS, the thresholds can be categorised as follows:

Less than 85%: Any queues that have built up will be able to disperse during the relevant stage in each cycle;

85-100%: Indicates that an arm is close to its theoretical capacity and any queue that have built up do not fully clear within each cycle; and

More than 100%: Indicates an arm is over its theoretical capacity with significant queueing likely to occur as a result.

4.3.4 A graphical representation of junction capacity is shown in Diagram 2 below.

Diagram 2 – Graphical representation of junction capacity.

4.3.5 For reference, the existing junction has been modelled using Junctions 8. The model has been

10



calibrated to reflect existing observed queue lengths as reported by AECOM. The junction delay and modelled queue is contained in Table 4-1.

Table 4-1 - 2016 Existing Junction Layout

JUNCTION ARM

2016 EXISTING TRAFFIC

AM PEAK PM PEAK

RFC MODELLED

QUEUE TOTAL

DELAY (S) RFC

MODELLED

QUEUE TOTAL

DELAY (S)

A2070 (S) Free Flow Conditions

Barrey Road 0.33 1 15 1.20 44 348

A2070 (N) (Right Turn) 0.31 1 12 0.23 1 11

4.3.6 The existing situation results reflect current observations, with the Barrey Road exit operating over capacity in the PM peak. There is minimal delay for vehicles turning right into Barrey Road from the A2070.

4.3.7 The existing junction layout has been modelled for the future year scenario, with the results contained in Table 4-2.

Table 4-2 - 2033 Existing Junction Layout

JUNCTION ARM

2033 FUTURE TRAFFIC

AM PEAK PM PEAK

RFC MODELLED

QUEUE TOTAL

DELAY (S) RFC

MODELLED

QUEUE TOTAL

DELAY (S)


Barrey Road 0.73 3 81 1.84 129 1411

A2070 (N) (Right Turn) 0.17 1 24 0.34 1 18

4.3.8 The results indicate that the future year traffic volumes will result in increased delays for Barrey Road in both the AM and PM peak periods, with significant increases in queue lengths in the PM peak as the junction breaches capacity. These queues result from the limited availability of suitable gaps for traffic exiting Barrey Road.

4.4 COST ESTIMATE

4.4.1 Construction cost estimates have been provided for all considered options.

4.4.2 The cost estimates provided have been based on quantities measured from OS mapping and the supplied topographic survey. No allowance has been made for diversion of utilities, planning approvals, surveys, detailed design of schemes, ground investigations and ongoing maintenance costs.

4.4.3 Given the above, the cost estimates should only be used for option ranking assessment purposes and not for contractual commitments or full budget estimating.

4.5 BENEFIT / COST RATIO

4.5.1 Proposals for junction improvements have been assessed on the annual benefit the scheme will deliver over the existing junction layout. Values for delay have been derived from junction modelling.

4.5.2 A Present Value of Benefit (PVB) has been calculated based on Spring 2016 WebTag values (release v1.5) to assess the impact on forecast values of time per vehicle class. A breakdown of vehicle classes has been taken from the traffic flows obtained by AECOM. The benefit is based on the difference in junction delay between the proposed scheme and the existing layout.

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4.6 OPTION ASSESSMENT SCORING

4.6.1 Option assessment has been based on a high / medium / low scoring of the following aspects:

4.6.2 Deliverability

High – Little or no disruption to existing layout and operation;

Medium – Manageable disruption to existing operation or layout; or

Low – Significant disruption or disturbance to existing operation or layout.

4.6.3 Integration within existing highway infrastructure

High – Changes to road marking and minor ancillary work only;

Medium – Minor adjustments / changes to highway infrastructure; or

Low – Significant changes / construction works and changes to the extent of the highway boundary.

4.6.4 Financial

High – minimal capital costs

Medium – average capital costs

Low – significant capital costs

4.6.5 Access improvements

High – Provides improved junction control and improved junction delay for both entry and exit;

Medium – Provides improved junction control and improved junction delay for either entry or exit; or

Low – No significant improvement in junction control or junction delay.

4.6.6 A2070 impacts

High – Minimal impact on through-flow traffic along the A2070;

Medium – Some impact on through-flow traffic along the A2070; or

Low – Impact / delay on through-flow traffic along the A2070.

4.6.7 The following section assesses each option providing a recommendation in Section 6.

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5 OPTION ASSESSMENT

5.1 INTRODUCTION

5.1.1 This report considers three options to upgrade the access at A2070/Barrey Road :

Option 1 – Provision of Nearside Merging Taper, with a sub-option providing a relocated pedestrian crossing of Barrey Road;

Option 2 – Roundabout control; and

Option 3 – Part-signalisation, with sub options providing for a splitter island variation to separate turning and through-traffic, and a further variation enhancing signal head numbers.

5.1.2 Set out below is the assessment of each option based on criteria set out in Section 4.

5.2 OPTION 1 - PROVISION OF NEARSIDE MERGING TAPER

INTRODUCTION

5.2.1 Option 1 is the addition of a nearside merging taper for traffic existing Barrey Road. This aids acceleration and merging for traffic turning left from Barrey Road and enables gaps to be selected more easily that were previously dismissed due to the opposing mainline traffic speeds. The lane will be of sufficient length for vehicles to accelerate from Barrey Road to speeds matching the mainline. An extract of the concept plan contained in Appendix A (Drawing Number 9540-SK-002) is provided below for ease of reference.

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5.2.2 The option will result in the need to make minor adjustments to the existing traffic island, and carriageway widening to the west, to accommodate the additional merging lane. The existing paved footway will need to be relocated to the west of the new merging lane, which may require an adjustment to existing services. The existing street lighting columns will need to be relocated to accommodate the required widening. The required merging length can be accommodated in the section of road before the narrowing at the footbridge structure.

5.2.3 An initial investigation has been carried out into the need for a nearside diverging taper for the A2070 left turn into Barrey Road but it has been considered unnecessary primarily due to the absence of recorded casualty data in respect of this manoeuver. A new nearside taper is not considered to provide any significant capacity benefit and may make it more difficult for NMU users to cross roads. It is also felt that the proposed speed limit reduction (as proposed by HE) will further reduce the likelihood and severity of future collisions. As such, no nearside diverging taper is proposed as part of this option.

5.2.4 Two options have been prepared for the provision of the nearside merging taper. Option 1A (Drawing Number 9540-SK-001) provides for pedestrian movement across Barrey Road at its current desire line. This will result in the pedestrian movement occurring at the acceleration lane for the left turn out which may be considered a safety risk. Option 1B (Drawing Number 9540-SK-002) relocates the pedestrian movement away from the acceleration lane to a potentially safer location, but does alter the pedestrian desire line to the east of the junction. Option 1B is considered to be the preferable layout as this provides a better margin between traffic and pedestrian interactions.

JUNCTION DELAY

5.2.5 Due to limitations in the Junctions 8 modelling software, the traffic modelling of the provision of a nearside merge taper produces similar junction delays to the existing junction. Vehicles exiting Barrey Road are still required to give way to mainline traffic flows on the A2070 and will be delayed if merge opportunities are not present.

5.2.6 As such, there is no improvement in junction delay over the existing layout. For reference, the results of the existing arrangement are repeated from Section 4 and are contained in Table 5-1 and the future year in Table 5-2.

Table 5-1 – 2016 Existing Junction Layout with nearside merge taper

JUNCTION ARM


AM PEAK PM PEAK

RFC MODELLED

QUEUE TOTAL

DELAY (S) RFC

MODELLED

QUEUE TOTAL

DELAY (S)


Barrey Road 0.33 1 15 1.20 44 348

A2070 (N) 0.31 1 12 0.23 1 11

Table 5-2 – 2033 Existing Junction Layout with nearside merge taper

JUNCTION ARM

2033 FUTURE TRAFFIC

AM PEAK PM PEAK

RFC MODELLED

QUEUE TOTAL

DELAY (S) RFC

MODELLED

QUEUE TOTAL

DELAY (S)


Barrey Road 0.73 3 81 1.84 129 1411

A2070 (N) 0.17 1 24 0.34 1 18

5.2.7 No improvements are provided for the right turn from A2070 into Barrey Road in this scheme and

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as such junction delay for the right turn is the same as the existing situation.

COST

5.2.8 The cost estimates for both Option 1A and Option 1B are estimated at approximately £300,000. This is considered a low-level capital cost.

BENEFIT COST RATIO

5.2.9 Given that the scheme delivers the same junction delay as the existing scheme, no Benefit Cost Ratio has been calculated.

ASSESSMENT SCORE

5.2.10 The assessment score and comments are contained in Table 5-3.

Table 5-3 - Assessment Score for Nearside Merge Taper

CRITERIA SCORE COMMENT

Deliverability MEDIUM

Works are required on the north-western arm of the junction only. The works can be delivered with manageable disruption during the construction phase.

Integration with existing highway infrastructure

MEDIUM

Only minor changes will be required to the existing highway infrastructure including minor road widening, kerb realignment and relocation of existing street lighting.

Financial HIGH The cost estimate for the scheme is in the order of a minimal capital cost.

Access Improvements LOW

This scheme provides no improvement for the right turn into Barrey Road. The left turn out is still required to find suitable gaps for merging onto A2070 without priority control.

A2070 Impacts HIGH There are no changes to A2070 movements or junction priority.

CONCLUSION

5.2.11 The scheme delivers no improvement to overall junction performance. The assessment score for the scheme indicates that there is little benefit delivered by the scheme and as such it is not recommended to pursue this option.

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5.3 OPTION 2 – ROUNDABOUT CONTROL

INTRODUCTION

5.3.1 Option 2 involves the construction of a roundabout at the junction of A2070/Barrey Road. The roundabout will provide for two approach and departure lanes in each direction on A2070, and one approach and departure lane on Barrey Road. An extract of the concept plan contained in Appendix B (Drawing Number 9540-SK-003) and is provided below for ease of reference.

5.3.2 The selection of a roundabout option at this location will provide benefit in off-peak situations where vehicle flows are low. Vehicles turning right into Barrey Road will have priority control over A2070 northbound movements. In off-peak situations, roundabouts generally have less vehicle delay than traffic signals. However, dominant flows on one or two approaches may lead to excessive delays on other approaches in high peak times as they struggle to find breaks in traffic to exit.

5.3.3 This option will require major construction work to deliver a new roundabout, which may significantly reduce mainline capacity. Changes will be required to the existing paved footway, which will need to be relocated further to the west. There will also be some carriageway widening to the east associated with the placement of the circulatory carriageway for the roundabout.

5.3.4 In order to contain the provision of the roundabout within the existing highway boundary, only minimal deflection has been achieved for A2070 southbound movements at the roundabout. It should be noted that although deflection is considered to be within the recommended DMRB TD16/07 standards, the deflection is limited and may result in higher vehicle speeds through the roundabout. Increased deflection could be created but this would require widening outside of the highway boundary if taken from the east or a short length of reverse curve introduced to the

16



northern approach. Both are considered equally undesirable.

5.3.5 The existing arrangement at the junction restricts Barrey Road traffic to a left turn only at A2070. The provision of a roundabout at this location would allow for an all moves junction to operate and create a new right turn out of Barrey Road. This would reduce the vehicle kilometres travelled for traffic travelling A2070 southbound as they would no longer have to travel to M20 junction 10 to perform a u-turn.

5.3.6 Base and future year traffic volumes have assumed that the existing junction layout is provided at the A2070/Barrey Road. As such, there are no traffic volumes provided for the right turn out of Barrey Road in the future scenario. An assumption has been made that a third of vehicles will turn right at the roundabout and two- thirds will turn left onto A2070.

5.3.7 The roundabout control would introduce delays for A2070 northbound, which would be required to give way to any vehicles turning right from A2070 onto Barrey Road.

JUNCTION DELAY

5.3.8 The junction delay and modelled queues for the base year are contained in Table 5-4.

Table 5-4 - 2016 Roundabout control

JUNCTION ARM


AM PEAK PM PEAK

RFC MODELLED

QUEUE TOTAL

DELAY (S) RFC

MODELLED

QUEUE TOTAL

DELAY (S)

A2070 (S) 0.92 12 22 0.91 10 19

Barrey Road 0.31 1 13 0.96 11 87

A2070 (N) 0.87 7 14 1.00 32 53

5.3.9 When compared to the existing junction layout (Table 4-1), the roundabout control improves the delay on Barrey Road by giving priority control and creating suitable gaps to enter the A2070. The modelled queue is significantly reduced in the PM peak. However, there is a newly introduced delay for the A2070 southbound movement. In the PM peak, all approaches are near, or are at, their capacity with queueing on A2070 northern arm.

5.3.10 The junction delay and modelled queues for the future year are contained in Table 5-5.

Table 5-5 - 2033 Roundabout control

JUNCTION ARM

2033 FUTURE TRAFFIC

AM PEAK PM PEAK

RFC MODELLED

QUEUE TOTAL

DELAY (S) RFC

MODELLED

QUEUE TOTAL

DELAY (S)

A2070 (S) 1.50 864 1384 1.23 275 450

Barrey Road 0.54 2 37 1.52 110 1332

A2070 (N) 1.16 194 296 1.84 1741 2784

5.3.11 When compared to the existing junction layout in the future year (Table 4-2), the roundabout slightly improves delay for Barrey Road. The roundabout however will be operating over its capacity and there will be significant delays and queueing on all approaches. Vehicles will experience significant delay in both the AM and PM peak periods.

5.3.12 The operation of the roundabout will only create suitable gaps for traffic exiting Barrey Road when traffic turns right from A2070 into Barrey Road. The turning counts supplied indicate that the number of vehicles performing this manoeuver is low and as such the number of suitable gaps created for traffic to exit Barrey Road is low, thus resulting in the poor junction performance.

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COST

5.3.13 The cost estimate for the provision of a roundabout is estimated at approximately £450,000. This would be considered a significant capital cost.

BENEFIT COST RATIO

5.3.14 The calculation of the Benefit Cost Ratio is contained in Table 5-6.

Table 5-6 – Benefit Cost Ratio of Roundabout Control

SCENARIO ELEMENT AM PEAK PM PEAK

Existing Layout Delay (pcuHr) 1.78 114.96

Delay (pcumins) 106.97 6,897.51

Proposed Layout Delay (pcuHr) 956.05 2,323.574

Delay (pcumins) 57,363.06 139,414.4

Difference Delay (pcumins) +57,256 +132,517

Annual Benefit -3,443,000 -7,396,000

Present Value of Benefits (PVB) -231,576,000

Present Value of Costs £450,000

Benefit to Cost Ratio -514.6

5.3.15 The scheme has a negative Benefit given that the total delay at the junction increases when compared to the existing layout. This is particularly evident in the PM peak, where the roundabout is operating above its capacity and has extensive queueing on all approaches.

ASSESSMENT SCORE


Table 5-7 - Assessment Score for Roundabout Control


Deliverability LOW There will be significant disruption to install this scheme.


LOW The scheme would create significant changes to the carriageway.

Financial LOW The cost estimate for the scheme is considered to be a significant capital cost.

Access Improvements HIGH

The provision of a roundabout will provide priority for the right turn into Barrey Road, which in turns creates suitable gaps for traffic to exit Barrey Road. The roundabout will also allow a right turn out of Barrey Road.

A2070 Impacts LOW

Northbound traffic onA2070 will be subject to priority control at the roundabout instead of free flowing conditions. Southbound traffic on A2070 will be required to give way to traffic exiting Barrey Road. Junction modelling indicates significant delays in future year scenarios.

18



CONCLUSION

5.3.17 The scheme delivers no improvement to junction performance. The assessment score for the scheme indicates that there is little benefit delivered by the scheme and as such it is not recommended to pursue this option

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5.4 OPTION 3 – PART-SIGNALISATION

INTRODUCTION

5.4.1 Option 3 involves the installation of traffic signals to control the existing turning movements. The junction would be part signalised, with all movements apart from A2070 southbound being subject to traffic signal control. The left turn only restriction out of Barrey Road would be retained. An extract of the concept plan contained in Appendix C (Drawing Number 9540-SK-006) is provided below for ease of reference.

5.4.2 The traffic signals would work in two stages. The first stage would see A2070 north / south movements under green conditions, with Barrey Road and the right turn into Barrey Road held on red. The second stage would hold the A2070 northbound on red, allowing the right turn into Barrey Road and the left turn out of Barrey Road to be under green conditions. No ‘all red’ pedestrian signal stage would be required with controlled pedestrian facilities operating under a “walk with traffic” arrangement.

5.4.3 The installation of traffic signals would run under MOVA control to allow signal staging to adapt to prevailing traffic flows. For the purpose of the modelling, cycle times have been set at 120 seconds. As would be expected, the majority of green time is given to the A2070 movements, reflecting the strategic nature of the road. Barrey Road is operating under a minimum phase green period.

5.4.4 Although a right turn out of Barrey Road could be provided to allow for southbound destinations, it is considered that the proposed new roundabout south of the M20 junction will provide an

20



adequate opportunity for vehicles to u-turn within a short distance. As such, no changes have been proposed to the current left turn only movement restriction at Barrey Road.

5.4.5 The option will result in the need to undertake minor works to install signalling equipment and changes to existing line markings. However, no alterations works are proposed to existing kerb lines, services or traffic islands. Some minor clearing of vegetation may be required to establish the required forward visibility to signal heads.

5.4.6 Three options have been prepared for the provision of part-signalisation. Option 3A (Drawing number 9540-SK-004) provides for signals with minimal construction or kerb alterations. Although a signal is provided for the A2070 southbound movement, these will be on a permanent green phase so traffic will never be required to stop. This signal has just been provided to prevent any possible confusion with the signalised southbound right turn. There is no physical separation in this option between traffic waiting to turn right into Barrey Road and through-route movement.

5.4.7 A traffic island can be constructed to separate A2070 southbound through-traffic from right turning traffic. This would allow for an additional signal head to be provided further separating the two vehicle streams. The construction of a traffic island is not a requirement under the DMRB, but it may be desirable to provide separation, enhance visibility and reduce possible confusion. The island would require new carriageway widening to accommodate the facility. For the construction of a traffic island, Option 3B (Drawing Number 9540-SK-005) does not provide for signal heads for A2070 through route traffic, which will save on construction costs. However, through route traffic will not have a green signal head, which may cause some confusion. Option 3C (Drawing Number 9540-SK-006) does provide for the additional green signal head so will carry a higher construction cost. Note there is no requirement to provide the additional signal heads under the DMRB guidance.

JUNCTION DELAY

5.4.8 The junction delay and modelled queues for all three signal options are the same, with the base year values contained in Table 5-8.

Table 5-8 – 2016 Part-Signalisation

JUNCTION ARM


AM PEAK PM PEAK

DEGREE OF

SATURATION

(%)

AVERAGE

DELAY (S) MEAN MAX

QUEUE

DEGREE OF

SATURATION

(%)

AVERAGE

DELAY (S) MEAN MAX

QUEUE

A2070 (N) 55.5 66 5 48.5 5 3

A2070 (S) 58.3 9 13 74.2 23 23

Barrey Road 57.8 71 5 73.5 52 14

Overall Junction

PRC: 11.7% Cycle Time: 120s PRC: 21.3% Cycle Time: 120s

5.4.9 When compared to the existing junction layout (Table 4-1), the part-signalisation improves the delay on Barrey Road by providing a dedicated green phase to enter/exit. The modelled queue is significantly reduced in the PM peak. The signals however do provide a red phase for vehicles on A2070 southern arm that currently has a free-flow configuration.

21



5.4.10 The junction delay and modelled queues for the future year scenario is contained in Table 5-9.

Table 5-9 – 2033 Part-Signalisation

JUNCTION ARM

2033 FUTURE TRAFFIC

AM PEAK PM PEAK

DEGREE OF

SATURATION

(%)

AVERAGE

DELAY (S) MEAN MAX

QUEUE

DEGREE OF

SATURATION

(%)

AVERAGE

DELAY (S) MEAN MAX

QUEUE

A2070 (N) 57.9 4 2 88.6 9.2 7

A2070 (S) 93.4 24 46 93.6 37 43

Barrey Road 85.6 132 6 91.2 84 18

Overall Junction

PRC: -3.8% Cycle Time: 120s PRC: -4.1% Cycle Time: 120s

5.4.11 When compared to the existing junction layout (Table 4-2), the part-signalisation improves the PM future year conditions for vehicles exiting Barrey Road. The junction is forecast to run near its capacity, with some delay introduced for the A2070 southern arm. In the AM peak, there is some increased delay along Barrey Road compared to the existing situation. This delay is due to the signal control restricting movements in times where traffic flows are lowever thereby delays and encountered. This delay may be overcome with adaptive signal timings giving additional green opportunities to Barrey Road in times of lower mainline flows. In addition, it is noted that the AM commuter peak hour does no coincide with the retail trading hours.

5.5 COST

5.5.1 The estimate for the part-signalisation of the junction is:

Option 3A (no separation of right / through traffic) – approximately £175,000

Option 3B (separation of right / through traffic) - approximately £200,000

Option 3C (separation of right / through traffic and additional signals) - approximately £250,000

5.5.2 These costs would be considered an average capital cost.

5.6 BENEFIT COST RATIO

5.6.1 The calculation of the Benefit Cost Ratio is contained in Table 5-10. Option 3C (separation of right / through traffic and additional signals) has been used for the scheme cost as this is the highest cost estimate.

Table 5-10 – Benefit Cost Ratio of Part-Signalisation

SCENARIO ELEMENT AM PEAK PM PEAK

Existing Layout Delay (pcuHr) 1.78 114.96

Delay (pcumins) 106.97 6,897.51

Proposed Layout Delay (pcuHr) 25.66 42.78

Delay (pcumins) 1,539.6 2,566.8

Difference Delay (pcumins) -1,433 +4,331

Annual Benefit -86,000 +242,000

Present Value of Benefits (PVB) +3,324,000

Construction Cost £250,000

Benefit to Cost Ratio 13.3

5.6.2 The scheme delivers a large annual benefit for the PM Peak by reducing vehicle delays for the Barrey Road exit. In the AM Peak the signals have introduced additional delay for Barrey Road exit and for A2070 northbound, and this is reflected as an annual disbenefit for the AM Peak.

22



Overall, when the AM and PM is combined, the scheme generates a total Present Value of Benefit of £3,324,000 which results in a Benefit to Cost Ratio of 13.3 for the larger scheme cost. The Benefit to Cost Raito value is high due to the significant improvements in the PM Peak period.

5.7 ASSESSMENT SCORE


Table 5-11 - Assessment Score for Part-Signalisation


Deliverability MEDIUM Construction works would be minor and limited to the installation of signal equipment and localised widening of the right turn lane


HIGH The works are proposing minimal works to install signal heads and a splitter island

Financial MEDIUM The cost estimate for the scheme is considered to be in the order of average capital cost.

Access Improvements HIGH Traffic entering / leaving Barrey Road would do so under signal control priority and as such there is no conflict with A2070 traffic.

A2070 Impacts MEDIUM

The signal control will introduce delays and queuing on A2070 northbound which currently operates in free flow conditions. There is no impact on A2070 southbound as they will not be subject to the signal control.

CONCLUSION

5.7.2 The scheme delivers significant improvement to junction performance. The assessment score for the scheme indicates that there is additional benefits delivered by the scheme for access improvements and integration with the existing highway infrastructure and as such it is recommended to pursue this option.

5.7.3 Of the three options provided for the part-signalisation, it is recommended that Option 3 Drawing Number 9540-SK-006 be pursued, as it provides a separation from right turn and through route traffic.

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6 SUMMARY AND CONCLUSION

6.1 SUMMARY

6.1.1 A summary of the option assessment score is shown in Table 6-1.

Table 6-1 - Summary Assessment Scores for Options

CRITERIA OPTION 1 –

NEARSIDE TAPER OPTION 2 -

ROUNDABOUT OPTION 3 – PART SIGNALISATION

Deliverability MEDIUM LOW MEDIUM


MEDIUM LOW HIGH

Financial HIGH LOW MEDIUM

Access Improvements LOW HIGH HIGH

A2070 Impacts HIGH LOW MEDIUM

6.2 RECOMMENDED SCHEME

6.2.1 The proposals for the upgrade of the A2070/Barrey Road junction aims to manage and create an appropriate gap for the entry / exit for vehicles to/from Barrey Road above what is currently provided.

6.2.2 The provision of part-signalisation addresses this aim and, on an option assessment score, provides a higher score than the other options of providing a nearside taper and the provision of roundabout control. The part-signalisation option will create suitable gaps through managed control and remove any conflict between Barrey Road and the A2070. In addition, the scheme has a positive Cost Benefit Ratio and delivers a positive annual benefit for the PM Peak improvements.

6.2.3 It is therefore recommended that the junction of A2070 Bad Munstereifel Road/Barrey Road is upgraded to a part-signalised junction in order to improve access to Barrey Road as per Drawing Number 9540-SK-006.

Appendix A

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Appendix B

ROUNDABOUT CONTROL

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KCC - Barrey Road

COST PLAN No.1

Main Summary

Ref Total Option 3A Average Risk 3A Total Option 3B Average Risk 3B Total Option 3C Average Risk 3C Comments on Principal Risk Max Risk 3A Min Risk 3A Max Risk 3B Min Risk 3B Max Risk 3C Min Risk 3C

1 £188,500 £28,275 £219,500 £32,925 £269,500 £40,425 Construction cost includes Optimism Bias at 44% Prelims increased from WSP Costs. £37,700 £18,850 £43,900 £21,950 £53,900 £26,950

2 Historic Costs (2014/15) £10,000 £0 £10,000 £0 £10,000 £0 Includes Outline Design to Date £0 £0 £0 £0 £0 £0

3 Business Case £15,000 £2,250 £15,000 £2,250 £15,000 £2,250 This may or may not be required. To be checked. £3,000 £1,500 £3,000 £1,500 £3,000 £1,500

4 Surveys & Studies £7,500 £750 £7,500 £750 £7,500 £750 £1,500 £0 £1,500 £0 £1,500 £0

5 Ecology/Archaeology Studies £0 £0 £0 £0 £0 £0 Unlikely to be required £0 £0 £0 £0 £0 £0

6 Landscape Enhancements £0 £1,000 £0 £1,000 £0 £1,000 Unlikely to be required as no landscaped areas. £2,000 £0 £2,000 £0 £2,000 £0

7 HE Costs £7,000 £500 £7,000 £500 £7,000 £500 To discuss with HE. £1,000 £0 £1,000 £0 £1,000 £0

8 Lane Rental £22,400 £1,120 £33,600 £1,680 £33,600 £1,680 based on £800/day, 7 days a week. Could be waved, could be more. £2,240 £0 £3,360 £0 £3,360 £0

9 Commuted Sums £60,000 £12,500 £50,000 £12,500 £80,000 £12,500 If required. Signals only. £20,000 £5,000 £20,000 £5,000 £20,000 £5,000

10 Inspection Fees £10,000 £1,000 £10,000 £1,000 £10,000 £1,000 Do we need this? £2,000 £0 £2,000 £0 £2,000 £0

11 Utilities £18,000 £3,000 £16,000 £3,000 £20,000 £3,000 No diversions anticipated but could be some comms and electrical connections to signals/signs. £4,000 £2,000 £4,000 £2,000 £4,000 £2,000

12 Public Enquiry £0 £0 £0 £0 £0 £0 Unlikely £0 £0 £0 £0 £0 £0

13 Planning Costs £0 £0 £0 £0 £0 £0 Not needed £0 £0 £0 £0 £0 £0

14 Land Costs & CPO £0 £0 £0 £0 £0 £0 All within existing highway boundary. Small piece of land outside. £0 £0 £0 £0 £0 £0

15 LCA Part 1 Costs £0 £0 £0 £0 £0 £0 It is likely that the bigger scheme will incur these but not this element alone. £0 £0 £0 £0 £0 £0

16 Agent's Costs (3%) £0 £0 £0 £0 £0 £0 No land costs so no Agent Fees £0 £0 £0 £0 £0 £0

17 Outline Design Fees (3%) £0 £2,500 £0 £2,500 £0 £2,500 Assume this has been done already and included in Historic Costs. Risk of more Options. £5,000 £0 £5,000 £0 £5,000 £0

18 Detailed Design Fees £50,000 £2,500 £50,000 £2,500 £50,000 £2,500 Based on time rather than % £5,000 £0 £5,000 £0 £5,000 £0

19 Supervision Fees £32,000 £6,000 £40,000 £6,000 £40,000 £6,000 Based on 6 weeks on site, 4 week lead-in and 12 month's defects £9,000 £3,000 £9,000 £3,000 £9,000 £3,000

20 KCC Internal Costs £6,000 £900 £7,000 £1,050 £7,000 £1,050 Ad-Hoc over 12 months 15% of PM team cost £1,200 £600 £1,400 £700 £1,400 £700

21 KCC Legal Costs £3,000 £450 £3,000 £450 £3,000 £450 Probably minimal, except for any agreement with ABC/HE £600 £300 £600 £300 £600 £300

VAT allowance for works not in existing highway £5,000 £750 £5,000 £750 £5,000 £750 Scope in the area unclear but a small piece of land is outside the existing highway. £1,000 £500 £1,000 £500 £1,000 £500

22 Cost in Use £0 £0 £0 £0 £0 £0 Included as Commuted Sum above £0 £0 £0 £0 £0 £0

Sub-Totals £434,400 £473,600 £557,600

23 Average Risk Total £64,909 £63,495 £70,501 £68,855 £78,376 £76,355 From Average Risk Total Includes Inflation Risk £95,240 £31,750 £102,760 £34,950 £112,760 £39,950

24 £9,425 £1,414 £10,975 £1,646 £13,475 £2,021 Inflation Risk in the period from estimate to completion £1,885 £943 £2,195 £1,098 £2,695 £1,348

£508,734 £64,909 £555,076 £70,501 £649,451 £78,376 Anticipated Total Cost Excluding Risk £97,125 £32,693 £104,955 £36,048 £115,455 £41,298

3A 3A 3B 3B 3C 3C

BASIS OF COSTS £532,000.00 £590,000 £687,000

WSP/Parsons Brinkerhoff Report 'A2070 Bad Munstereifel Road/Barrey Road Options Study May 2017' Anticipated Minimum Cost £477,000 £521,000 £613,000

Final Draft

Item Description

Construction Costs as WSP Estimate 24.04.2017

Inflation from 2Q17 to commencement, assumed 1Q18

Anticipated Maximum Cost

Anticipated Total Cost

Page 2 ADD/JS/KCC26/C1/Item 7 App C (002).xlsx

Documents

Ashford Joint Transportation Board · 1 To: Ashford Joint Transportation Board By: KCC Highways, Transportation & Waste Date: 13th June 2017 Subject: A2070/Barrey Road junction Classification: