ROAD SAFETY AUDIT - massdot.state.ma.us · ROAD SAFETY AUDIT Interchange of Routes 9 and 20 Town of Northborough November, 2012 Prepared by: Howard/Stein-Hudson Associates 38 Chauncy

ROAD SAFETY AUDIT

Interchange of Routes 9 and 20

Town of Northborough

November, 2012

Prepared by: Howard/Stein-Hudson Associates

38 Chauncy Street Boston, MA 02111

Prepared for: Massachusetts Department of Transportation

Road Safety Audit Interchange of Routes 9 and 20, Northborough, MA Prepared by Howard/Stein-Hudson Associates, Inc.

Table of Contents Background ................................................................................................................................. 2

Project Data................................................................................................................................. 4

Project Location Description ..................................................................................................... 4

Road Safety Audit Observations ...............................................................................................9 Ramp #1. Route 20 on-ramp to Route 9 westbound ......................................................... 10 Ramp #2. Route 9 westbound off-ramp to Route 20 westbound....................................... 13 Ramp #3. Route 9 westbound off-ramp to Route 20 eastbound ........................................ 15 Ramp #4. Route 9 eastbound off-ramp to Route 20 eastbound......................................... 17 Ramp #5. Route 20 on-ramp to Route 9 eastbound ........................................................... 19 Ramp #6. Route 9 eastbound off-ramp to Route 20 westbound........................................ 22 Area-Wide Observations ................................................................................................................... 23

Potential Safety Enhancements ...............................................................................................26

List of Appendices

Appendix A. RSA Meeting Agenda Appendix B. RSA Audit Team Contact List Appendix C. Detailed Crash Data Appendix D. Additional Information

List of Figures

Figure 1. Locus Map.............................................................................................................................. 3 Figure 2. Interchange of Routes 9 and 20 .............................................................................................. 7

List of Tables

Table 1. Participating Audit Team Members ....................................................................................... 4 Table 2. Summary of Potential Safety Enhancements ....................................................................... 27

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Background The interchange of Routes 9 and 20 falls within the Top 5% of High Crash Locations within the Central Massachusetts Regional Planning Commission (CMRPC) area. During the Road Safety Audit (RSA), the team focused on safety issues at each of the six ramps within the interchange as well as general safety issues along Routes 9 and 20 in the vicinity of the interchange. The study area is illustrated in Figure 1.

From October 1, 2011 to August 28, 2012, 110 crashes were reported at the interchange, plus 67 additional incidents involving less than $1,000 worth of damage; this time period is following the completion of the recent ramp reconfiguration at the interchange, which was completed around October 2011. A review of historic crash data at the interchange reveals a substantial increase in crashes from just 8 crashes in 2009, and 15 crashes in 2010, to approximately 68 crashes in 2011. The total number of crashes from 2011 to 2012 nearly doubled.

According to team members, the increase in crashes at the interchange is directly related to the increase in traffic volume associated with the significant increase in new residential and commercial development in the area. Most notably, a development of approximately 175-acres consisting of approximately 600,000 square feet of retail called Northborough Crossing, and approximately 400 units of housing called Avalon Northborough, is located approximately 0.25 miles from the interchange and was completed in October 2011. As part of mitigation to help offset the new traffic these developments would bring, the interchange, which had been a traditional cloverleaf, was reconfigured in an effort to reduce weaving along Route 9. The Route 20 eastbound on-ramp to Route 9 westbound was removed and replaced with a signalized left-turn lane on Route 20 eastbound, which provides access to the existing Route 20 westbound on-ramp to Route 9 westbound. The Route 20 westbound on-ramp to Route 9 eastbound was also removed and replaced with a signalized left-turn lane on Route 20 westbound, which connects to the existing Route 20 eastbound on-ramp to Route 9 eastbound. MassDOT also recently resurfaced Route 20 (MassDOT Project #606151), which was completed in October 2012.

MassDOT has determined that the Town of Northborough would be eligible to receive Highway Safety Improvement Program (HSIP) funding for construction/implementation of safety enhancements at the interchange if a Road Safety Audit (RSA) were conducted and the proposed design incorporates the safety improvements identified in the RSA.

In general, the RSA is intended to identify potential safety improvements that can be evaluated and included as part of future design efforts for reconstruction. The short-term, low-cost potential improvements could be considered by the responsible agency for implementation prior to reconstruction, as appropriate.

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RSA Study Area

Belmont Street (Route 9)

Southwest Cuto

ff (Route 20)

AvalonNorthborough

Nortborough CrossingShopping Center

(completed)

South

westCuto

ff(R

oute20

)

Econolodge Inn,JJ’s Sports Bar

and Grill

Sears Outlet,Christmas Tree Shops,

and Other Retail

Road Safety Audit Interchange of Routes 9 and 20, Northborough, MA

Figure 1. Locus Map

Belmont Street (Route 9)

Southwest Cuto

ff (Route 20)

Avalon Northborough

Nortborough Crossing Shopping Center

(completed)

South

westCuto

ff(R

oute20

)

Econolodge Inn, JJ’s Sports Bar

and Grill

Sears Outlet, Christmas Tree Shops,

and Other Retail

Not to scale.

RSA Study Area

Source: Google Maps

Howard/Stein-Hudson Associates, Inc.


Project Data The audit team conducted an RSA at the interchange of Routes 9 and 20 on Wednesday, November 7, 2012. The RSA agenda appears in Appendix A. Table 1 lists the audit team members and their affiliations. Appendix B provides contact information for all team members.

Prior to the RSA, in order to begin assessing possible safety issues, the team reviewed collision diagrams and crash detail summaries for the interchange, based on crash records supplied by the Northborough Police Department. Appendix C provides the detailed crash data for the study area. Speed regulation data is provided in Appendix D.

Table 1. Participating Audit Team Members Audit Team Member Agency/Affiliation Promise Otaluka Federal Highway Administration Alolade Campbell MassDOT District 3 Traffic

Joe Frawley MassDOT District 3 Traffic Bill Lyver Northborough Police Chief Mark Leahy Northborough Police

Kevin Krasnecky Central Massachusetts Regional Planning Commission (CMRPC) Sujatha Mohanakrishnan Central Massachusetts Regional Planning Commission (CMRPC) Dan Daniska Central Massachusetts Regional Planning Commission (CMRPC)

Dan Mason Northborough DPW David M. Durgin Northborough Fire/EMS John W. Coderre Northborough Town Administrator

Silpa Munukutla MassDOT Corey O’Connor MassDOT Highway Division Lisa Schletzbaum MassDOT Highway Division Joe SanClemente Howard/Stein-Hudson (HSH)

Mike Tremblay Howard/Stein-Hudson (HSH)

Project Location Description The RSA focused on safety issues at the interchange of Routes 9 and 20 in the town of Northborough. Route 9 is a major state highway that provides connections to I-495, I-90, and I-290. Route 20 provides access to downtown Northborough as well as major retail and local residential uses. The interchange is located just south of a large newly-completed retail development called Northborough Crossing, which contains a BJ’s Wholesale Club, Dicks Sporting Goods, Wegman’s Wine, Liquor and Beer Shop, Kohls, and other retail locations, which can be accessed from Route 20. Also north of the interchange on Route 20 is a newly completed residential development called Avalon Northborough, which consists of about 400 residential units. Econo Lodge Inn and Suites and JJ’s Sports Bar and Grill are located adjacent to the interchange in the southwest quadrant, and are provided with access on Route 9 eastbound and on Route 20. A large shopping center, containing a Sears Outlet, Christmas Tree Shops, and other

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establishments, lies approximately 0.30 miles west of the interchange, and can be accessed from Route 9 eastbound and from Route 20.

The interchange is formed by the junction of the following roadways, which are categorized according to MassDOT Office of Transportation Planning functional classifications:

Route 9 (Belmont Street) is classified as an urban principal arterial and falls under MassDOT jurisdiction. Route 9 generally runs in an east-west direction, originating at Copley Square in Boston as Huntington Avenue in the east, and terminating in Pittsfield as East Street to the west. Within the study area, Route 9 is generally two lanes in each direction and divided by a concrete barrier. The speed limit is posted at 50 miles per hour (mph) within the study area.

Route 20 (Southwest Cutoff) is classified as an urban principal arterial and falls under MassDOT jurisdiction. Route 20 in Massachusetts generally runs in an east-west direction, originating at Kenmore Square in Boston as Commonwealth Avenue to the east, and runs to the New York state line in Hancock. Within the study area, Route 20 runs in a north-south direction; with eastbound traffic traveling in a northerly direction and westbound traffic traveling in a southerly direction. Within the audit study area, Route 20 westbound opens up to two through lanes beginning at Shops Way. These two westbound through lanes continue past the study area. Directly south of the audit study area, Route 20 carries two eastbound lanes, with one lane splitting off to the Route 9 eastbound ramp. Single lane eastbound traffic continues through north of the study area. The speed limit is posted at 45 mph near the study area.

The RSA team focused on the following six ramp locations within the interchange (see Figure 2):

1. Route 20 on-ramp to Route 9 westbound (located on the northwest quadrant of the interchange); 2. Route 9 westbound off-ramp to Route 20 westbound (northwest quadrant); 3. Route 9 westbound off-ramp to Route 20 eastbound (northeast quadrant); 4. Route 9 eastbound off-ramp to Route 20 eastbound (southeast quadrant); 5. Route 20 on-ramp to Route 9 eastbound (southeast quadrant); and 6. Route 9 eastbound off-ramp to Route 20 westbound (southwest quadrant).

The RSA team also discussed general safety issues within and around the interchange. The six ramp locations are described below.

Ramp #1: Route 20 on-ramp to Route 9 westbound (northwest quadrant) is a one-lane ramp that begins on Route 20, approximately 650 feet north of the Route 9 bridge over Route 20, and connects to Route 9 westbound approximately 700 feet west of the bridge. The ramp provides access to Route 9 westbound from both directions on Route 20. Vehicles traveling on Route 20 eastbound are provided with a dedicated left-turn lane and signal to access the ramp. Vehicles traveling on Route 20 westbound may travel freely onto the ramp. The on-ramp intersects Route 9 westbound at an acute angle and operates under stop sign control. An acceleration lane onto Route 9 is not provided.

Ramp #2: Route 9 westbound off-ramp to Route 20 westbound (northwest quadrant) is a one-lane ramp that begins on Route 9 westbound, just west of the Route 9 bridge over Route 20, and connects to Route

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20 westbound, just north of the bridge. Vehicles traveling on Route 9 westbound may travel freely onto the ramp. The ramp intersects Route 20 at an acute angle and operates under stop sign control.

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S Signal

Ramp NumberX

Rout

e 20 On

ramp to

Route 9 WB

Rout

e 9W

B offramp to Route 20 WB

Route 9 EB Offra

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EB

Route 9 EB Offramp to Route 20WB

S

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Econolodge Inn,JJ’s Sports Bar

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Belmont Street (Route 9)Sout

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Route 20 Onramp to

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Route 9 WB Offramp to Route 20 EB

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Road Safety Audit Interchange of Routes 9 and 20, Northborough, MA

Figure 2. Interchange of Route 9 and Route 20

R o u t

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o R o u t e 9 W B

R o u t

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B o ff ramp to Route 20 WB

Route 9 EB Offra

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Route 9 EB Offramp to Route 20WB

S

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Econolodge Inn, JJ’ s Spo rt s Bar

and Grill

Belmont Street (Route 9)Sout

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(Rou

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)

Route 20 Onramp to

Route9 EB

Route 9 WB Offramp to Route 20 EB

1 2

6 4

3

5

Not to scale.

S Signal

Ramp NumberX

Source: Google Maps

Howard/Stein-Hudson Associates, Inc.


Ramp #3: Route 9 westbound off-ramp to Route 20 eastbound (northeast quadrant) is a one-lane ramp that begins on Route 9 westbound, east of the Route 9 bridge over Route 20, and connects to Route 20 eastbound approximately 650 feet north of Route 9. The ramp intersects Route 20 directly across from the Route 20 on-ramp to Route 9 westbound. Vehicles traveling westbound on Route 9 may travel freely onto the ramp; a deceleration lane of approximately 300 feet is provided. The ramp intersects Route 20 at an acute angle and is controlled by a signal, where right turns on red are permitted.

Ramp #4: Route 9 eastbound off-ramp to Route 20 eastbound (southeast quadrant) is a one-lane ramp that begins on Route 9 eastbound, just east of the bridge over Route 20, and connects to Route 20 eastbound just south of the bridge. Vehicles traveling on Route 9 eastbound may freely enter the ramp; however, there is no deceleration lane approaching the ramp. The ramp intersects with Route 20 at eastbound at an acute angle and is stop-controlled.

Ramp #5: Route 20 on-ramp to Route 9 eastbound (southeast quadrant) is a straight ramp that begins on Route 20, approximately 900 feet south of the Route 9 bridge over Route 20, and connects to Route 9 eastbound, approximately 700 feet east of the bridge. Vehicles traveling on Route 20 eastbound may freely enter the ramp. Vehicles traveling westbound on Route 20 access the ramp using a signalized left-turn lane.

Ramp #6: Route 9 eastbound off-ramp to Route 20 westbound (southwest quadrant) is a one-lane ramp that begins on Route 9 eastbound, approximately 700 feet west of the Route 9 bridge over Route 20, and connects to Route 20 westbound, approximately 550 feet south of the interchange. Vehicles entering the ramp from Route 9 eastbound may freely enter the ramp; a deceleration lane is provided in advance of the off-ramp that also accommodates vehicles accessing the retail uses west of the ramp. The ramp intersects Route 20 at an acute angle and operates under stop-control.

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Road Safety Audit Observations Based on field observations on Wednesday, November 7, the RSA team determined that the interchange of Routes 9 and Route 20 has the following issues that affect safety:

Constrained ramp geometry; Motorist confusion; Confusing and/or hard to see signage; Queuing and driver frustration; Limited visibility of signal indications; Lack of acceleration/deceleration lanes; and High travel speeds.

The following sections describe in more detail the safety issues and potential enhancements determined during the RSA. Several of these issues require further study and engineering judgment to determine the feasibility of implementing enhancements to address them.

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Ramp #1. Route 20 on-ramp to Route 9 westbound

Observations: Of the 110 crashes that were reported within the interchange between October 1, 2011 and August 28, 2012, 65 (59%) occurred on the Route 20 ramp to Route 9 westbound.

Of the 65 crashes, 59 occurred at the end of the ramp at its intersection with Route 9, including 58 (98%) rear-end crashes and one (2%) single-vehicle crash involving a motorist who swerved in order to avoid a rear-end collision but struck a stop sign instead. These crashes were generally a result of driver inattention, following too closely, or other improper actions.

The remaining six of the 65 crashes at this ramp (9%), occurred at the entrance to the on-ramp, including three angle-type crashes (50%), two single-vehicle crashes (33%), and one rear-end crash (17%). One of the two single-vehicle crashes involved a dump truck that forgot to lower the back bed and struck the overhead mast arm, knocking it down, and eliminating the video detection at the signal. The other single-vehicle crash involved a motorist who struck a deer just north of the entrance to the ramp.

The following details the observations with respect to ramp geometry, travel speeds, and signal indications:

Ramp Geometry and Travel Speeds

The Route 20 on-ramp intersects Route 9 westbound at an acute angle and operates under stop control; however, no acceleration lane onto Route 9 westbound is provided. Meanwhile, motorists traveling along Route 9 westbound generally travel well in excess of the posted speed limit of 50 mph, making it extremely difficult for motorists to accelerate from a complete stop to 50 mph or greater in order to merge with Route 9 traffic.

As a result motorists often “roll through” the stop sign so that they can more easily get up to speed with traffic on Route 9. RSA team members commented that the word “STOP” was recently painted at the stop bar, which seems to have reduced the number of motorists that roll through; however, those familiar with the intersection still typically roll through.

Since the ramp intersects Route 9 at an acute angle, motorists either at or approaching the stop line must then look over their left shoulder to see on-coming traffic to judge if they have an

The Route 20 on-ramp to Route 9 westbound is stop controlled, making it difficult for motorists to merge onto Route 9 westbound.

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adequate gap in the passing traffic stream; however, the sight line of oncoming traffic on Route 9 is partially limited by the presence of a group of trees and other vegetation just east of the ramp. RSA team members commented that motorists often begin looking towards oncoming traffic as soon as possible to begin looking for an acceptable gap in traffic, and do not anticipate stopped vehicles ahead of them on the ramp.

Signage

The ramp’s approach to Route 9 westbound operates under stop-control and is provided with two stop signs, one on each side of the ramp. An RSA team member noted that the stop sign on left-hand side of the ramp is posted mounted on the same post as a guide sign for Route 9 westbound. Another team member commented that this guide sign seemed unnecessary.

The District recently installed Stop Ahead (W3-1) warning signs in September, 2012. Thus, before these signs were installed, crashes may have occurred because motorists unfamiliar with the area may not have expected that they needed to stop and/or that there may have been queuing as they approached Route 9.

Signal Indications

Of the six crashes reported at the entrance to the ramp at Route 20, one involved a dump truck traveling along Route 20 westbound that forgot to lower its bed and struck the overhead mast arm, knocking it down, and eliminated the video detection at the signal. As a result of this crash, a temporary signal indication and post were placed on the southern corner of the Route 20 on-ramp to Route 9 west, adjacent to Route 20 for Route 20 westbound for Route 20 westbound; however, video detection is currently not provided and the signal is operating on maximum recall settings.

Three of the crashes were angle-type crashes involving vehicles turning left from Route 20 eastbound onto the on-ramp with vehicles traveling on Route 20 westbound. At least two of the three angle-type crashes were attributed to a motorist running a red light. RSA team members commented that these crashes were likely the result of the video detection not working

Visibility of the temporary signal for Route 20 westbound is blocked by signage.

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as it was reported that some motorists had become confused/frustrated with the lack of detection and were running red lights.

RSA team members noted that the temporary signal indication for Route 20 westbound, on a nonstandard pole, was blocked from view by guide and warning signage as of the date of the RSA. Limited visibility of the Route 20 westbound signal indication may have contributed to the rear-end crash involving two westbound vehicles. A new mast arm was installed in November, 2012, shortly after the RSA was completed; however, a team member noted that detection still is not functioning properly.

Potential Enhancements:

1. Consider the appropriateness of replacing existing stop signs (R1-1) at the end of the ramp with oversized signage and add retroreflective tape on sign posts to improve their visibility.

2. Consider the appropriateness of providing speed advisory signage (W13-3) at the entrance to the ramp to reduce speeds on the ramp.

3. Consider the appropriateness of trimming, or removing, the group of trees located just east of the ramp approach so that vehicles traveling on the ramp can see oncoming traffic traveling along Route 9 westbound.

4. Remove guide sign for Route 9 located at the end of the ramp on the left-hand side and relocate the existing stop sign to a separate post.

5. Consider the feasibility of adding an acceleration lane on Route 9 westbound to facilitate a safe merge from the ramp; replace signage as appropriate.

6. Verify that video detection gets replaced and functions properly.

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Ramp #2. Route 9 westbound off-ramp to Route 20 westbound

Observations: Of the 110 crashes reported at the interchange, 14 (or 13%) occurred along the Route 9 westbound off-ramp to Route 20 westbound. All of the crashes were rear-end crashes and occurred at the ramp’s intersection with Route 20 westbound. Three of the crashes resulted in personal injury.

The following details the observations with respect to ramp geometry and signage.

Ramp Geometry

At the beginning of the ramp on Route 9, no deceleration lane is currently provided. Thus, motorists entering the ramp must decelerate from 50 mph or more within the travel lane onto a ramp with a tight radius. Team members observed that vehicles, that were continuing westbound on Route 9, generally drive aggressively as motorists attempt to slow down to turn onto the ramp.

Once on the ramp, the small radius makes it difficult for motorists to slow down and to perceive and react to the approaching queue stopped at the stop line at Route 20.

Furthermore, sight lines on the ramp are limited due to the presence of trees and other vegetation on the inside of the curve, which makes it difficult for motorists to see cars queued at the stop line. One of the reported crashes at this location occurred when a motorist noticed a fast-moving car approaching from behind – the motorist then attempted to pull away, but hit the car ahead in the queue. Team members commented that the queue often backs up to Route 9.

The Route 9 westbound off-ramp intersects Route 20 westbound at an acute angle.

At the end of the ramp, the ramp approach intersects Route 20 westbound at an acute angle, making it difficult for motorists to see oncoming traffic over their left shoulder, while watching out for the vehicle in front of them. One of the reported crashes occurred when the first vehicle stopped at the stop line moved forward, then stopped quickly, causing a rear-end collision with a second vehicle.

Signage

Two stop signs are currently located at the end of the ramp at its intersection with Route 20 westbound. During field observations, it was noted that one of these stop signs was tilted as if it had been hit. RSA team members also noted that there are no ramp speed advisory or chevron signs on the ramp to warn motorists. The District recently installed Stop Ahead (W3-1) warning signage in September, 2012.

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Potential Enhancements: 1. Consider the feasibility and safety benefits of softening the radius of the off-ramp and

creating a T-intersection at the end of the off-ramp at Route 20 westbound to improve sight lines.

2. Consider the appropriateness of adding signalization to the ramp at its intersection with Route 20 if a signal is warranted at the location, while considering impacts to the ramp’s capacity. Also consider queue detection to prevent vehicle backup onto Route 9.

3. Maintain, and/or remove, trees/vegetation on the inside radius of the ramp so that approaching vehicles can see vehicles queuing at the ramp’s stop line at Route 20.

4. Consider providing additional ramp speed advisory signage (W13-3), and/or chevrons, at the entrance to the ramp to warn motorists to reduce speeds on the ramp.

5. Consider replacing existing advanced “Stop Ahead” (W3-1) sign along the ramp with one equipped with flashing lights to improve visibility, to further encourage caution when approaching Route 20.

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Ramp #3. Route 9 westbound off-ramp to Route 20 eastbound

Observations: Six (5%) of the 110 reported crashes that occurred at the interchange of Routes 9 and 20 occurred at the Route 9 westbound off-ramp to Route 20 eastbound. All of these crashes were rear-end crashes and occurred at the ramp’s intersection with Route 20 eastbound; one crash resulted in personal injury.

The following details the observations with respect to ramp geometry, signal indications, and signage.

Ramp Geometry

The horizontal and vertical curvature of the ramp combined with the tree line on the inside of the curve limits sight lines for motorists approaching the back of the queue stopped at the end of the ramp. The downhill slope on the ramp also encourages faster speeds as vehicle approach the stop line.

The ramp then intersects Route 20 eastbound at an acute angle and operates under signal control, where right turns on red are permitted. An RSA team member commented that site lines west of the stop line along Route 20 are limited due to the presence of overgrown vegetation on the south side of the roadway. The acute intersection angle, combined with the sight distance limitations, makes it difficult for motorists to see oncoming traffic when attempting to turn right on red.

Signal Indications

At the intersection with Route 20 eastbound, the ramp is provided with two overhead signal indications on a mast arm. Right-turns on red are permitted; however, RSA team members noted that vehicles often stop past the stop line in order to see oncoming traffic on Route 20 due to the sight distance limitations west of the ramp. As a result these motorists have difficultly seeing the overhead indications. One of the reported crashes involved a vehicle that was delayed at a green light and was rear-ended by a motorist who assumed that the vehicle had passed through the signal.

Signage

RSA team members noted that there are no speed advisory signs on the ramp to warn motorists.

Vehicles queued on Route 9 westbound off-ramp at Route 20

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Potential Enhancements: 1. Consider the appropriateness and safety benefits of providing a supplemental signal

indication at the end of the ramp to improve visibility of the signal indications for vehicles either stopped at, or approaching, the stop line.

2. Consider the feasibility of repositioning or reorienting existing signal heads so that they are more visible to motorists at or ahead of the stop line.

3. Consider providing additional ramp speed advisory signage (W13-3) at the entrance to the ramp to reduce speeds on the ramp.

4. Consider the appropriateness of providing advanced “Signal Ahead” (W3-3) signage on the ramp.

5. Consider trimming overgrown vegetation along the south side of Route 20 to improve sightlines for vehicles attempting to make a right turn on red at the ramp stop line.

6. Consider trimming overgrown vegetation along the north side of the ramp to improve the visibility of the signal indications and the back of the traffic queue.

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Ramp #4. Route 9 eastbound off-ramp to Route 20 eastbound

Observations: Five (5%) of the 110 crashes that occurred at the interchange of Routes 9 and 20 between October 1, 2011 and August 28, 2012 occurred at the Route 9 eastbound off-ramp to Route 20 eastbound. All of these crashes were rear-end crashes and occurred at the end of the ramp at its intersection with Route 20 eastbound.

At the beginning of the ramp, no deceleration lane is provided along Route 9 eastbound. Thus, vehicles entering the ramp must slow down from 50 mph or more on the ramp, which has a tight turning radius. The ramp’s tight radius and downhill slope combined with vegetation on the inside of the radius makes it difficult for vehicles on the ramp to see oncoming traffic on Route 20. Furthermore, the ramp is also on a downgrade towards Route 20, potentially making it difficult to stop on a slippery road surface. According to the crash data, two of the five rear-end crashes occurred on wet pavement.

The ramp then intersects Route 20 eastbound at an acute angle and operates under stop sign control; no acceleration lane for vehicles to safely merge onto Route 20. Once at the stop line, or as they approach, motorists must then look over their left shoulder in order to find an acceptable gap in traffic, all while watching for vehicles in front of them in the queue. During the field visit, team members observed vehicle queues that extended nearly up to Route 9 and that some motorists did not stop at the stop sign. Queuing conditions on the ramp may contribute to driver inattention and the occurrence of rear-end crashes at this approach; four of the five rear-end crashes reported were attributed to driver inattention.

Meanwhile on Route 20 eastbound, there is only one travel lane in the vicinity of the ramp, due to a Route 9 bridge abutment. Team members commented that the heavy traffic conditions in one travel lane combined with the lack of an acceleration lane makes it difficult for motorists waiting at the stop line to find an acceptable gap when turning onto Route 20. Long queues entering Route 20

eastbound from Route 9 eastbound.

There is no acceleration lane on Route 20 eastbound due to a bridge abutment.

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Potential Enhancements: 1. Consider the feasibility of softening the radius of the off-ramp to create a T-intersection

between the Route 9 eastbound off-ramp to Route 20 eastbound, which would make it easier for vehicles to merge onto Route 20 and make it easier for queued vehicles to see to approaching vehicles.

2. Consider providing additional ramp speed advisory signage (W13-3) and chevrons along the ramp to warn motorist and reduce speeds on the ramp.

3. Consider the appropriateness of providing advanced “Stop Ahead” (W3-1) signage on the ramp.

4. As part of long-term planning efforts with bridge reconstruction, consider adding an acceleration lane along Route 20 eastbound.

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Ramp #5. Route 20 on-ramp to Route 9 eastbound

Observations: Nine crashes were reported on the Route 20 on-ramp to Route 9 eastbound between October 1, 2011 and August 28, 2012. Eight (89%) of these crashes were rear-end crashes, and one (11%) was a single-vehicle crash.

Vehicles traveling along Route 20 eastbound are provided with a dedicated lane leading to the on-ramp. As part of the recent resurfacing of Route 20, new guide signage and pavement markings are provided along Route 20 eastbound, including pavement markings within the on-ramp indicating “TO 9 EAST”. Vehicles entering the ramp from Route 20 westbound are provided with a dedicated, signalized left-turn lane that accesses a separate ramp that intersects with the Route 20 eastbound on-ramp to Route 9 eastbound.

The Route 20 eastbound and westbound ramps are each provided with separate lanes, designated by a dashed white lane line, for a short distance, before eventually merging into one lane. However, team members noted that the markings may still be in a temporary condition, which may add to confusion among motorists about how many lanes there are in the merge area. The speed limit on Route 20 is 50 mph, and vehicles entering the ramp from Route 20 eastbound generally do not slow as they are provided with an acceleration lane on Route 9. During the audit, team member members noted that vehicles making the left-turn onto the ramp generally stop if they see a vehicle approach on the ramp from Route 20 eastbound since they are typically driving at a high rate of speed.

Of the nine crashes reported on the ramp between October 1, 2011 and August 28, 2012, four involved rear-end crashes between vehicles entering the ramp from Route 20 westbound, two involved rear-end crashes between two vehicles entering from Route 20 eastbound, and one involved a rear-end crash where a vehicle entering from Route 20 westbound was rear-ended by a vehicle entering from Route 20 eastbound. At least two of the rear-end crashes involving two vehicles entering from Route 20 westbound occurred because one vehicle slowed or stopped suddenly to yield to traffic entering from Route 20 eastbound. Both crashes involving two vehicles entering from Route 20 eastbound involved vehicles slowing or stopping to yield to vehicles entering from Route 20 westbound; one of these crashes resulted in personal injury.

Team members commented that the number of crashes during 2011/2012 at this ramp location may be partially attributed to confusion before/during the recent resurfacing and may not reflect the improvements to signage pavement markings.

Route 20 eastbound traffic may enter the on-ramp to Route 9 eastbound without slowing down.

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Route 20 westbound currently has no signal control south of the Route 9 bridge, including the Route 9 eastbound off-ramp to Route 20 westbound, which is not signal-controlled despite its proximity to a traffic signal that controls entrance to the Route 20 on-ramp to Route 9 eastbound.

Lastly, a team member commented that Route 20 westbound is provided with a signalized left-turn lane, while the Route 20 westbound through lanes are uncontrolled movements; as such motorists traveling through along Route 20 westbound may be confused by a red signal indication intended for the left-turn lane. A team member noted that it may be confusing for motorists that Route 9 eastbound ramp to Route 20 westbound is stop-controlled when it is in such close proximity to a signalized intersection.

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Potential Enhancements: 1. Consider the safety benefits re-striping the existing dashed white lane line to a solid white

lane line to reinforce that traffic from Route 20 eastbound and Route 20 westbound may travel in two separate lanes for a short distance. Consider the use of recessed pavement markings for increased visibility.

2. Consider the appropriateness and safety benefits of implementing geometric changes to force a deliberate right-turn from Route 20 eastbound onto the ramp to decrease speeds on the ramp if pavement marking improvements do not reduce the number of crashes on the ramp.

3. Evaluate the intersection control for all approaches and consider modifications to reduce potential driver confusion.

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Ramp #6. Route 9 eastbound off-ramp to Route 20 westbound

Observations: No crashes were reported on the Route 9 off-ramp to Route 20 westbound; however, RSA team members observed skid marks on the recently resurfaced ramp just upstream of the stop line at Route 20. Since the ramp is stop-controlled, and sightlines appear to be adequate, the skid marks may indicate that motorists may be entering the ramp at a high rate of speed, and that travel speeds on the ramp may be high.

Along Route 9 eastbound, a wide outside travel lane is provided of the off-ramp that appears wide enough to provide a separate deceleration line; however, clear pavement markings are not provided delineating the deceleration lane

Potential Enhancements: 1. Consider the appropriateness of providing additional ramp speed advisory signage (W13-3)

and chevrons along the ramp to warn motorist and reduce speeds on the ramp.

2. Consider the feasibility of using pavement markings to delineate the deceleration lane to clarify lane use for motorists.

Skid marks were observed on the ramp, which was recently resurfaced.

Page 22


Area-Wide Observations

Observations: In addition to observations at the individual ramps, the RSA team also identified general safety issues within and around the vicinity of the interchange.

The following details the observations with respect to drainage, lighting, signage, weather, and long-term planning.

Drainage

RSA team members noted that Route 20 can become flooded in the vicinity of the Route 9 overpass. It was suggested that leaves and other debris build up in the catch basins, clogging them. An RSA team member noted that flooding is sometimes so severe that vehicles stall in the roadway.

Lighting

RSA team members suggested that the new interchange configuration can be confusing to motorists who are unfamiliar with the interchange, and that confusion is amplified when it is dark outside. Three of the 13 crashes that occurred on the Route 20 mainline between October 1, 2011 and August 28, 2012 occurred after dark, including one vehicle that struck a deer.

Signage

The RSA team noted that the interchange can be confusing to motorists unfamiliar with the area, and that there are more of these motorists than ever due to the new developments that have been built over the last three years. RSA team members noted several instances of signage that was unnecessary, redundant, or not visible to motorists. One crash occurred when a motorist traveling on Route 20 westbound stopped suddenly because he was looking for the entrance to the on-ramp to Route 9 that he had already passed. The guide sign for the entrance to the Route 9 eastbound ramp the motorist was likely looking for is located very close to the underpass under Route 9, and is not visible until the motorist is already in the underpass. The same problem occurs along route 20, where the visibility of the guide sign for Route 9 westbound is blocked by the bridge abutment.

RSA team members also stated that lane use along Route 20 is unclear as there is limited lane use signage to indicate lane use. Finally, a team member commented that some motorists unfamiliar with the area may be misled by out-of-date maps and GPS devices.

Guide signage on Route 20 is not visible until motorists are under the underpass.

Page 23


Weather

RSA team members noted that the time period that the crash data was taken (October 1, 2011 through August 28, 2012) had few instances of snow; however, due to a mild winter in 2011/2012, it is not known how safe the interchange with the new configuration will operate in snow weather conditions or when ice is on the road. Two of the 110 crashes reported in the time frame occurred when snow was on the roadway.

Just after the RSA was completed, a team member noted that a motorist appeared to have lost control of his vehicle on a snow-covered surface, running over the curb, and hitting a guide sign, at the Route 20 westbound off-ramp to Route 9 eastbound.

Long-Term Planning

In an effort to reduce weaving along Route 9, and to accommodate expected increases in traffic volumes in the area, two of the ramps at the interchange were removed and traffic signals were installed along Route 20. Team members noted that the existing Route 9 bridge and abutments limit the capacity along Route 20 and the ability to perform any widening of Route 9 within the interchange, restricting the ability to add deceleration lanes for traffic utilizing the two remaining loop ramps.

Potential Enhancements: 1. Remove debris from all drainage structures along Route 20, where possible, to help

minimize flooding on Route 20.

2. Consider the safety benefits of adding additional lighting along Route 9 and Route 20 within the study area, particularly at ramp intersections and major commercial driveways, while considering the costs of power and maintenance.

3. Relocate guide signage along Route 20 eastbound for Route 9 westbound that is currently blocked by the bridge abutment so that it is more visible.

4. Relocate guide signage along Route 20 westbound for Route 9 eastbound that is currently blocked by the bridge abutment so that it is more visible.

5. Reevaluate all guide signage in the vicinity of the interchange and remove unnecessary signage, relocate difficult-to-see signage to more visible areas, and consider the use of overhead guide/lane use signage where feasible.

A vehicle that appears to have slid off the road in snowy conditions just after the RSA.

Page 24


6. Monitor safety conditions at the interchange during snow/ice conditions for impact to future redesign efforts.

7. As part of long-term planning considerations, reevaluate interchange configuration, geometry, and traffic control. Consider the safety benefits of widening Route 9 and Route 20 to accommodate geometric changes such as the addition of acceleration and deceleration lanes, etc.

Page 25


Potential Safety Enhancements Based on its observations and discussions, the RSA team identified the issues and possible enhancements that could improve safety at the interchange of Route 9 and 20 in Northborough. Many of the enhancements identified during the RSA may require further design work or consideration to determine the feasibility of making some of the improvements.

Short-term enhancements include:

Trim overgrown vegetation;

Maintain drainage structures;

Improve pavement markings; and

Improve signage.

To enhance the safety of the intersection, the long-term enhancements are to:

Improve interchange geometry;

Improve queuing/operating conditions;

Improve guide and wayfinding signage; and

Improve lane use markings.

Table 2 summarizes these safety issues, possible enhancements, estimated safety payoff, time frame, cost, and responsibility. Safety payoff estimates are based on engineering judgment and are categorized as low, medium, and high. The time frame is categorized as short-term (<1 year), mid-term (1 to 3 years), or long-term (typically >3 years). Long-term improvements are typically considered to be substantial improvements with an expected time frame for implementation greater than 3 years. The costs are categorized as low (<$10,000), medium ($10,000 to $50,000), or high (>$50,000). It is the responsibility of MassDOT to ensure that the designer incorporates the relevant safety enhancements identified as part of this RSA. The RSA is intended to identify potential safety improvements that can be evaluated and included as part of the design process for the reconstruction. The short-term low-cost potential improvements could be considered by the responsible agency for implementation prior to reconstruction.

Page 26


Table 2. Summary of Potential Safety Enhancements

Location Safety Enhancement Safety Payoff

Time Frame Cost Responsibility

Consider the appropriateness of replacing existing stop signs (R1-1) at the end of the ramp with oversized signage and add retroreflective tape on sign posts to improve their visibility.

Low Short-term

Medium MassDOT

Ramp #1: Route 20 on-ramp to Route 9 westbound

Consider the appropriateness of providing speed advisory signage (W13-3) at the entrance to the ramp to reduce speeds on the ramp.

Low Short-term

High MassDOT

Consider the appropriateness of trimming, or removing, the group of trees located just east of the ramp approach so that vehicles traveling on the ramp can see oncoming traffic traveling along Route 9 westbound

Low Short-term

Low MassDOT

Remove guide sign for Route 9 located at the end of the ramp on the left-hand side and relocate the existing stop sign to a separate post.

Low Short-term

Low MassDOT

Consider the feasibility of adding an acceleration lane on Route 9 westbound to facilitate a safe merge from the ramp; replace signage as appropriate.

High Long-term

High MassDOT

Page 27


Table 2. Summary of Potential Safety Enhancements (Continued)



Consider the feasibility and safety benefits of softening the radius of the off-ramp and creating a T-intersection at the end of the off-ramp at Route 20 westbound to improve sight lines.

High Long-term

High MassDOT

Ramp #2: Route 9 westbound off-ramp to Route 20 westbound

Consider the appropriateness of adding signalization to the ramp at its intersection with Route 20 if a signal is warranted at the location, while considering impacts to the ramp’s capacity. Also consider queue detection to prevent vehicle backup onto Route 9.

High Long-term

High MassDOT

Maintain, and/or remove, trees/vegetation on the inside radius of the ramp so that approaching vehicles can see vehicles queuing at the ramp’s stop line at Route 20.

Low Short-term

Low MassDOT

Consider providing additional ramp speed advisory signage (W13-3), and/or chevrons, at the entrance to the ramp to warn motorists to reduce speeds on the ramp.

Low Short-term

Low MassDOT

Consider replacing existing advanced “Stop Ahead” (W3-1) sign along the ramp, with one equipped with flashing lights to improve visibility, to further encourage caution when approaching Route 20.

Low Short-term

Medium MassDOT

Page 28





Consider the appropriateness and safety benefits of providing a supplemental signal indication at the end of the ramp to improve visibility of the signal indication for vehicles either stopped at, or approaching, the stop line.

Medium Mid-term

Medium MassDOT

Ramp #3: Route 9 westbound off-ramp to Route 20 eastbound

Consider the feasibility of repositioning or reorienting existing signal heads so that they are more visible to motorists at or ahead of the stop line.

Low Short-term

Low MassDOT

Consider providing additional ramp speed advisory signage (W13-3) at the entrance to the ramp to reduce speeds on the ramp.

Low Short-term

Low MassDOT

Consider the appropriateness of providing advanced “Signal Ahead” (W3-3) signage on the ramp.

Low Short-term

Low MassDOT

Consider trimming overgrown vegetation along the south side of Route 20 to improve sightlines for vehicles attempting to make a right turn on red at the ramp stop line.

Low Short-term

Low MassDOT

Consider trimming overgrown vegetation along the north side of the ramp to improve the visibility of the signal indications and the back of the traffic queue.

Low Short-term

Low MassDOT

Page 29





Ramp #4: Route 9 eastbound off-ramp to Route 20 eastbound

Consider the feasibility of softening the radius of the off-ramp to create a T-intersection between the Route 9 eastbound off-ramp to Route 20 eastbound, which would make it easier for vehicles to merge onto Route 20 and make it easier for queued vehicles to see to approaching vehicles.

High Long-term

High MassDOT

Consider providing additional ramp speed advisory signage (W13-3) and chevrons along the ramp to warn motorists and reduce speeds on the ramp.

Low Short-term

Low MassDOT

Consider the appropriateness of providing advanced “Stop Ahead” (W3-1) signage on the ramp.

Low Short-term

Low MassDOT

Ramp #5: Route 20 on-ramp to Route 9 eastbound

Consider the safety benefits re-striping the existing dashed white lane line to a solid white lane line to reinforce that traffic from Route 20 eastbound and Route 20 westbound may travel in two separate lanes for a short distance. Consider the use of recessed pavement markings for increased visibility.

Medium Short-term

Low MassDOT

Consider the appropriateness and safety benefits of implementing geometric changes to force a deliberate right-turn from Route 20 eastbound onto the ramp to decrease speeds on the ramp if pavement marking improvements do not reduce the number of crashes on the ramp.

High Long-term

High MassDOT

Ramp #6: Route 9 eastbound off-ramp to Route 20 westbound

Consider the appropriateness of providing additional ramp speed advisory signage (W13-3) and chevrons along the ramp to warn motorist and reduce speeds on the ramp.

Low Short-term

Low MassDOT

Add control improvements at the ramp’s intersection with Route 20.

Medium Mid-term

Medium MassDOT

Consider the feasibility of using pavement markings to delineate the deceleration lane to clarify lane use for motorists.

Low Short-term

Low MassDOT

Page 30





Remove debris from all drainage structures along Route 20, where possible, to help minimize flooding on Route 20.

Low Short-term

Low MassDOT

Consider the safety benefits of adding additional lighting along Route 9 and Route 20 within the study area, particularly at ramp intersections and major commercial driveways.

Medium Long-term

High MassDOT

Relocate guide signage along Route 20 eastbound for Route 9 westbound that is currently blocked by the bridge abutment so that it is more visible.

Low Short-term

Low MassDOT

Area-Wide Relocate guide signage along Route 20 westbound for Route 9 eastbound that is currently blocked by the bridge abutment so that it is more visible.

Medium Short-term

Low MassDOT

Reevaluate all guide signage in the vicinity of the interchange and remove unnecessary signage, relocate difficult-to-see signage to more visible areas, and consider the use of overhead guide/lane use signage where feasible.

Low Long-term

Medium MassDOT

Monitor safety conditions at the interchange during snow/ice conditions for impact to future redesign efforts.

Low Long-term

Low

MassDOT/Central Massachusetts Regional Planning Commission (CMRPC)

Page 31





Area-Wide

As part of long-term planning considerations, reevaluate interchange configuration, geometry, and all traffic control. Consider the safety benefits of widening Route 9 to accommodate geometric changes such as the addition of acceleration and deceleration lanes, etc.

High Long-Term

High

MassDOT/ Central Massachusetts Regional Planning Commission (CMRPC)

Page 32


Appendix A. RSA Meeting Agenda


Appendix B. RSA Audit Team Contact List


Appendix C. Detailed Crash Data

Crash Data Summary Table Intersection of Belmont St. (Rt. 9) and Southwest Cutoff Rt. 20; Northborough, MA

10/1/2011 - 8/28/2012

#

Crash Date Crash Day Time of Day Manner of Collision Light Condition

Weather Condition Road Surface Driver Contributing Code Ages Comments

m/d/y Type Type Type Type Type D1 D2 D3 1 8/28/12 Tuesday 2:17 PM Rear-end Daylight Clear Dry Other improper action 44 57 2 8/27/12 Monday 2:55 PM Rear-end Daylight Clear Dry Inattention 48 28 3 8/25/12 Saturday 3:23 PM Rear-end Daylight Clear Dry Other improper action 56 39 4 8/25/12 Saturday 7:10 PM Rear-end Dusk Clear Dry Inattention 64 18

5 8/24/12 Friday 11:17 AM Rear-end Daylight Clear Dry Other improper action 31 31 Vehicle 1 began to pull forward and then stopped quickly causing Vehicle 2 to rear-end it

6 8/21/12 Tuesday 10:11 AM Rear-end Daylight Clear Dry Other improper action 55 29 Vehicle 1 delayed on green light, Vehicle 2 assumed Vehicle 1 already pulled forward

7 8/9/12 Thursday 1:11 PM Rear-end Daylight Clear Dry Other improper action 23 71 8 8/8/12 Wednesday 1:02 PM Rear-end Daylight Clear Dry Other improper action 67 23 9 8/8/12 Wednesday 1:28 PM Rear-end Daylight Clear Dry Other improper action 75 19 10 8/5/12 Sunday 11:46 AM Rear-end Daylight Clear Dry Other improper action 36 32 11 8/3/12 Friday 3:41 PM Rear-end Daylight Clear Dry Followed too closely 36 49 12 8/3/12 Friday 12:19 PM Rear-end Daylight Clear Dry Inattention 24 48

13 7/30/12 Monday 6:33 PM Angle Daylight Clear Dry Distracted 18 74 Operator 2 was distracted while waiving to an uninvolved vehicle and possibly failed to stop for red light

14 7/27/12 Friday 9:55 AM Rear-end Daylight Cloudy Dry Inattention 25 50 Vehicle 1 was yielding to merging traffic which caused Vehicle 2 to rear-end it 15 7/27/12 Friday 8:02 AM Rear-end Daylight Cloudy Dry Inattention 67 23 16 7/25/12 Wednesday 4:35 PM Head on Daylight Clear Dry Failed to yield to right of way 49 29

17 7/20/12 Friday 11:15 PM Rear-end Dark - lighted roadway Clear Dry Disregarded traffic signs, signals, road markings 52 41

18 7/19/12 Thursday 8:26 PM Rear-end Dusk Clear Dry Inattention 42 26

19 7/19/12 Thursday 3:30 PM Single Vehicle Crash Daylight Clear Dry Other improper action 63

Vehicle 1 pulled to side of street thinking that an uninvolved vehicle behind her was going to pass. In doing so Vehicle 1 struck the curbing causing 2 flat tires.

20 7/17/12 Tuesday 4:50 PM Rear-end Daylight Clear Dry Inattention 49 45 21 7/16/12 Monday 5:34 PM Rear-end Daylight Clear Dry Failed to yield to right of way 54 43 22 7/13/12 Friday 9:32 PM Single Vehicle Crash Dark - lighted roadway Clear Dry Inattention 37 25 23 7/11/12 Wednesday 7:36 PM Rear-end Daylight Clear Dry Inattention 51 27 24 7/11/12 Wednesday 5:10 PM Rear-end Daylight Clear Dry Inattention 49 19 25 7/9/12 Monday 7:04 PM Rear-end Daylight Clear Dry Inattention 40 43

26 7/7/12 Saturday 6:10 PM Rear-end Daylight Clear Dry Disregarded traffic signs, signals, road markings 28 19

27 7/6/12 Friday 3:57 PM Rear-end Daylight Clear Dry Inattention 37 28 28 7/2/12 Monday 6:56 PM Rear-end Daylight Cloudy Dry Inattention 65 21 29 6/25/12 Monday 9:27 PM Rear-end Dark - lighted roadway Cloudy Wet Inattention 30 22

30 6/19/12 Tuesday 6:49 PM Rear-end Daylight Clear Dry Inattention 60 26 Vehicle 1 began to pull forward and then stopped quickly due to emergency vehicles traveling on Rt 9 causing Vehicle 2 to rear-end it

31 6/15/12 Friday 4:06 PM Angle Daylight Clear Dry Disregarded traffic signs, signals, road markings 41 47 Vehicle 2 failed to stop at red light

32 6/12/12 Tuesday 11:44 AM Rear-end Daylight Clear Dry Inattention 51 17 33 6/7/12 Thursday 7:24 AM Rear-end Daylight Clear Dry Inattention 26 25 34 6/3/12 Sunday 11:47 AM Rear-end Daylight Clear Dry Other improper action 42 42 35 6/1/12 Friday 8:43 PM Rear-end Dark - lighted roadway Cloudy Dry Inattention 66 19 36 5/30/12 Wednesday 1:39 PM Rear-end Daylight Clear Dry Other improper action 48 62

37 5/26/12 Saturday 11:12 AM Angle Daylight Cloudy Dry Made an improper turn 30 39 Vehicle 1 attempted to enter parking lot by crossing double solid line & multiple lanes of traffic

38 5/26/12 Saturday 2:25 PM Rear-end Daylight Clear Dry Other improper action 49 17

39 5/22/12 Tuesday 10:47 PM Single Vehicle Crash Dark - lighted roadway Cloudy Wet Inattention 22 Vehicle swerved off road to avoid hitting vehicle stopped at stop sign. Ended up hitting the stop sign on the side of road instead.

40 5/22/12 Tuesday 1:38 PM Rear-end Daylight Rain Wet Inattention 35 23 41 5/18/12 Friday 6:59 PM Rear-end Dusk Clear Dry Inattention 26 34 42 5/17/12 Thursday 12:52 AM Single Vehicle Crash Dark - lighted roadway Clear Dry Inattention 38 Dump truck forgot to lower back bed and struck overhanging light pole 43 5/7/12 Monday 8:30 PM Rear-end Dark - lighted roadway Clear Dry Inattention 38 21 44 5/6/12 Sunday 7:21 PM Rear-end Daylight Clear Dry Inattention 63 80 45 5/5/12 Saturday 8:52 AM Rear-end Daylight Cloudy Dry Inattention 57 22 46 5/3/12 Thursday 7:02 PM Rear-end Daylight Cloudy Wet Inattention 33 57 47 5/1/12 Tuesday 2:23 PM Rear-end Daylight Rain Wet Inattention 27 18 48 4/14/12 Saturday 12:22 AM Single Vehicle Crash Dark - lighted roadway Clear Dry No Improper Driving 36 Struck deer in roadway 49 4/18/12 Wednesday 8:39 PM Rear-end Dark - lighted roadway Clear Dry Inattention 33 16 50 4/10/12 Tuesday 7:42 PM Rear-end Dark - lighted roadway Clear Dry Inattention 32 72


10/1/2011 - 8/28/2012

#



m/d/y Type Type Type Type Type D1 D2 D3

51 4/10/12 Tuesday 7:05 PM Rear-end Daylight Clear Dry Inattention 36 50 Vehicle 1 stopped to avoid collision with uninvolved vehicle, Vehicle 2 was not looking and rear-ended Vehicle 1


53 4/5/12 Thursday 6:10 PM Single Vehicle Crash Daylight Clear Dry Inattention 62 Vehicle accelerates off road and hits brick wall in driveway of #380 SW Cutoff. Operator claims to have been cut off by an unknown vehicle.

54 3/31/12 Saturday 1:59 PM Rear-end Daylight Clear Dry Other improper action 77 52 55 3/24/12 Saturday 3:35 PM Rear-end Daylight Clear Dry Other improper action 69 35 56 3/23/12 Friday 10:46 AM Rear-end Daylight Clear Dry Inattention 53 32 57 3/22/12 Thursday 8:36 AM Rear-end Daylight Clear Dry Inattention 54 48

58 3/15/12 Thursday 7:12 PM Rear-end Dark - lighted roadway Cloudy Dry Disregarded traffic signs, signals, road markings 55 16

59 3/15/12 Thursday 3:02 PM Rear-end Daylight Clear Dry Other improper action 72 17 Vehicle 1 stopped suddenly while looking for the on-ramp to Rt 9 which he had already passed

60 3/11/12 Sunday 11:12 AM Rear-end Daylight Clear Dry Followed too closely 27 22

61 3/10/12 Saturday 11:14 PM Single Vehicle Crash Dark - lighted roadway Clear Dry No Improper Driving 18 Operator herd a large "bang" and lost steering to vehicle causing it to strike a large wooden sign.

62 3/9/12 Friday 3:16 PM Rear-end Daylight Clear Dry Inattention 26 21 Vehicle 1 stopped because of crash on the off-ramp, Vehicle 2 could not stop in time

63 3/9/12 Friday 3:08 PM Rear-end Daylight Cloudy Dry Other improper action 51 39 64 3/4/12 Sunday 11:44 AM Rear-end Daylight Clear Dry Other improper action 38 17

65 3/2/12 Friday 6:59 PM Rear-end Dark - lighted roadway Cloudy Dry Disregarded traffic signs, signals, road markings 64 unk Hit and run crash

66 2/24/12 Friday 4:41 PM Rear-end Daylight Rain Wet Inattention 60 58

67 2/18/12 Saturday 6:24 PM Angle Dark - lighted roadway Clear Dry Failure to keep in proper lane or running off road unk 61

Vehicle 2 crossed over a painted traffic island in an attempt to enter #375 SW Cutoff


69 2/13/12 Monday 12:33 PM Rear-end Daylight Clear Dry No Improper Driving 36 59 Vehicle 1 stopped for uninvolved TT unit in front, Vehicle 2 rear-ended Vehicle 1

70 2/6/12 Monday 12:43 PM Rear-end Daylight Clear Dry No Improper Driving 63 25

Vehicle 1 and 2 were both stopped at stop sign. In an attempt to avoid being rear-ended by an unknown, fast approaching vehicle , Vehicle 2 tries to pull away, making contact with Vehicle 1

71 1/30/12 Monday 7:36 AM Head on Daylight Clear Dry Failed to yield to right of way 55 20 72 1/28/12 Saturday 5:10 PM Rear-end Dusk Clear Dry Inattention 39 23 73 1/28/12 Saturday 4:11 PM Rear-end Daylight Clear Dry Inattention 29 17 74 1/25/12 Wednesday 3:42 PM Rear-end Daylight Clear Dry Other improper action 64 33

75 1/25/12 Wednesday 12:11 PM Rear-end Daylight Clear Dry Other improper action 59 45 Operator 2 claims to have pushed in on the clutch and brakes but car moved forward rear-ending Vehicle 1

76 1/22/12 Sunday 4:49 PM Rear-end Daylight Cloudy Wet Inattention 59 23 77 1/22/12 Sunday 11:05 AM Rear-end Daylight Clear Wet Other improper action 27 53 78 1/21/12 Saturday 9:18 AM Single Vehicle Crash Daylight Snow Snow No Improper Driving 30 Vehicle applied brakes, lost control of vehicle and hit median barrier 79 1/14/12 Saturday 3:26 PM Rear-end Daylight Clear Dry Inattention 25 65 80 1/12/12 Thursday 1:50 PM Rear-end Daylight Cloudy Wet Other improper action 65 51 81 1/12/12 Thursday 9:50 AM Rear-end Daylight Snow Snow Other improper action 48 54 Road conditions were slippery with snow

82 1/10/12 Tuesday 10:40 PM Rear-end Dark - lighted roadway Clear Dry No Improper Driving 65 22 unk Vehicle 3 rear ended Vehicle 1 which then rear-ended Vehicle 2. Vehicle 3 left the scene

83 12/30/11 Friday 1:44 PM Rear-end Daylight Cloudy Dry Inattention 45 42 84 12/29/11 Thursday 12:28 PM Rear-end Daylight Clear Dry Other improper action 27 22 85 12/28/11 Wednesday 10:04 PM Rear-end Dark - lighted roadway Clear Dry Inattention 29 39 86 12/26/11 Monday 8:30 AM Rear-end Daylight Clear Dry Other improper action 60 23 87 12/19/11 Monday 6:01 PM Rear-end Dark - lighted roadway Clear Dry Inattention 43 74 88 12/17/11 Saturday 3:10 PM Rear-end Daylight Clear Dry Inattention 39 25 89 12/15/11 Thursday 5:41 PM Rear-end Dark - lighted roadway Rain Wet Inattention 53 51 90 12/14/11 Wednesday 7:13 PM Rear-end Dark - lighted roadway Clear Dry No Improper Driving 53 19 91 12/12/11 Monday 5:52 PM Rear-end Dark - lighted roadway Clear Dry Inattention 42 26 Vehicle 1 slowed down to merge with traffic causing Vehicle 2 to rear-end it 92 12/8/11 Thursday 8:19 PM Rear-end Dark - lighted roadway Clear Dry Inattention 29 20 93 12/6/11 Tuesday 3:22 PM Rear-end Daylight Rain Wet Inattention 30 59 94 12/3/11 Saturday 5:54 PM Rear-end Dark - lighted roadway Clear Dry Inattention 28 43 95 12/1/11 Thursday 2:12 PM Rear-end Daylight Clear Dry Inattention 52 30 96 11/26/11 Saturday 2:11 PM Rear-end Daylight Clear Dry Other improper action 70 16 97 11/22/11 Tuesday 5:36 PM Rear-end Dark - lighted roadway Clear Dry Inattention 41 57 98 11/14/11 Monday 11:26 AM Rear-end Daylight Clear Dry Other improper action 61 44 99 11/9/11 Wednesday 2:21 PM Rear-end Daylight Clear Dry Inattention 72 51 100 11/6/11 Sunday 4:05 PM Rear-end Dusk Clear Dry Inattention 51 22


10/1/2011 - 8/28/2012

#



m/d/y Type Type Type Type Type D1 D2 D3

101 10/25/11 Tuesday 8:23 AM Sideswipe, same direction Daylight Clear Dry Inattention 57 50 Vehicle 2 side-swiped the corner of Vehicle 1's trailer which had been disconnected from tractor unit

102 10/22/11 Saturday 2:48 PM Rear-end Daylight Clear Dry Inattention 40 63

103 10/20/11 Thursday 7:40 PM Rear-end Dusk Clear Dry Disregarded traffic signs, signals, road markings 40 40

104 10/19/11 Wednesday 11:25 AM Single Vehicle Crash Daylight Rain Wet Over-correcting/over-steering 62 Operator claims that there was a mechanical failure that made the vehicle turn to the right & hit brush on side of road

105 10/16/11 Sunday 1:52 PM Rear-end Daylight Clear Dry Inattention 37 18 106 10/15/11 Saturday 1:54 PM Rear-end Daylight Rain Wet Inattention 25 47 107 10/14/11 Friday 7:00 PM Rear-end Dark - lighted roadway Clear Dry Inattention 37 64 108 10/8/11 Saturday 12:38 PM Rear-end Daylight Clear Dry Inattention 62 42 109 10/7/11 Friday 10:50 AM Rear-end Daylight Clear Dry Inattention 56 21 110 10/2/11 Sunday 1:16 PM Rear-end Daylight Cloudy Wet Failed to yield to right of way 55 55

Summary based on Crash Reports obtained from the Northborough Police Department. 15 operator reports and 52 incident reports were also located at this site but were not included in investigation data.

Crash Data Summary Tables and Charts Intersection of Belmont St. (Rt. 9) and Southwest Cutoff Rt. 20; Northborough, MA

0%

5%

10%

15%

20%

CRASH MONTH

11%

5%

11%

5%

11%

6%

15% 11%

0%

9%

5%

12%

J F M A M J J A S O N D

**Note data was only taken from October 2011 to August 2012

0%

5%

10%

15%

20%

25% CRASH DAY OF WEEK

13%

18%

13% 13%

20% 18%

5%

Monday Tuesday Wednesday Thursday Friday Saturday Sunday

0%

10%

20%

30%

40% CRASH TIME OF DAY

7%

24% 27%

35%

7% 0%

6-10AM 10-2PM 2-6PM 6-10PM 10-2AM 2-6AM

0%

20%

40%

60%

80%

100% CRASH MANNER OF COLLISION

8%

85%

4% 1% 0% 2% 0% 0%

Single Vehicle Crash

Rear-end Angle Sideswipe, same

direction

Sideswipe, opposite direction

Head on Rear to Rear

Unknown

Crash Summary Data Table_10_10_12 4 of 5 10/10/2012

Crash Data Summary Tables and Charts Intersection of Belmont St. (Rt. 9) and Southwest Cutoff Rt. 20; Northborough, MA

0% 20% 40% 60% 80% 73%

Daylight

CRASH LIGHT CONDITION

0% 5% 22%

0% 0% 0%

Dawn Dusk Dark -Lighted

Roadway

Dark -Roadway not lighted

Dark -unknown roadway lighting

Other

0%

Unknown

0%

20%

40%

60%

80%

100% 77%

Cle

ar

CRASH WEATHER CONDITION

15% 6% 2% 0% 0% 0% 0% 0%

Clo

udy

Rai

n

Sno

w

Sle

et, H

ail,

Fre

ezin

gR

ain

Fog

, Sm

og,

Sm

oke

Sev

ere

Cro

ssw

inds

Blo

win

gsa

nd, s

now

Oth

er

0%

Unk

now

n

0%

20%

40%

60%

80%

100% 85%

Dry

CRASH ROAD SURFACE

13% 2% 0% 0% 0% 0% 0%

Wet Snow Ice Sand, mud, dirt, oil, gravel

Water (standing, moving)

Slush Other

0%

Unknown

0%

10%

20%

30%

9%

15-20

CRASH DRIVER AGES

25%

16% 16% 18% 12%

4%

21-29 30-39 40-49 50-59 60-69 70-79

0%

80+

Crash Summary Data Table_10_10_12 5 of 5 10/10/2012


Appendix D. Additional Information

Documents

ROAD SAFETY AUDIT - massdot.state.ma.us · ROAD SAFETY AUDIT Interchange of Routes 9 and 20 Town of Northborough November, 2012 Prepared by: Howard/Stein-Hudson Associates 38 Chauncy