Office of Highway Safety Road Safety Audit Review

Transcription

1 Office of Highway Safety Road Safety Audit Review Town: Londonderry Date Reviewed: August 21, 2018 Route: Town Highway 2: Thompsonburg, Main St Mile points: Entire Length Location Map 1 of 48

2 Office of Highway Safety Road Safety Audit Review RSAR Process A Road Safety Audit Review (RSAR) is a formal examination of an existing road in which an independent, multi-discipline team (the Audit Team) reports on potential safety issues. According to the Federal Highway Administration (FHWA), Figure 1 - Road Safety the purpose of a RSAR is to determine which elements of Audit Process the road may present a safety concern, to what extent and under what circumstances as well as to identify opportunities to mitigate the identified safety concerns. The RSAR process is composed of several steps as shown in Figure 1. The process starts with a Commencement Meeting during which the Audit Team reviews data and gathers community concerns. A Site Inspection is then performed by the Audit Team. The site visit involves the identification of safety deficiencies as seen in the field. The Audit Team will usually drive through the location of interest to get a feel for the area, traveling through each approach in the case of intersections. The team is to then drive at a slower speed to make observations. If needed, the team will also walk the location. Following the site inspection, the Audit Team holds a Post Inspection Meeting. It is during this meeting that the team members discuss their observations and identify safety issues. The team is to reach a consensus on the importance of each safety issue mentioned. Only those issues for which a consensus is reached are included in the RSAR findings. A RSAR report (Written Report) is prepared. The Written Report identifies safety concerns and proposes guidance. These issues and solutions are presented in a tabular format associated to each Responsible Entity for 2 of 48

3 Office of Highway Safety Road Safety Audit Review ease of reporting. The Responsible Entities are any groups who own a roadway feature or who are responsible for making an improvement or for initiating further studies. These could include for example, the VTrans design section, the local town, the local police or the local RPC. Location The location of this RSAR is Town Highway 2 from about Rowes Road to VT 11. Town Highway 2 is referred to as Thompsonburg Road north of Rowes Road and to Main Street south of Rowes Road. Purpose of the RSAR This RSAR was conducted at the request of the Town of Londonderry. The RSAR herein has sought to identify potential safety hazards and physical features which may affect road user safety. However, it is possible that not every deficiency has been identified. It should further be recognized that the implementation of the guidance in this report might contribute to improve the level of safety of the facility reviewed but not necessarily remove all the risks. RSAR Participants Mario Dupigny-Giroux from the Office of Highway Safety, VTrans, was the RSAR coordinator. The other participants were: Nicholas Bredice, Ross Gouin, John Gruchacz, Bill Jenkins, Kelsi Record, George Mora, Matthew Rawson, Kelly Capin, Jeff Nugent, Traffic Design, VTrans Bike/Ped Program, VTrans Development Review, VTrans GHSP, VTrans Traffic Design, VTrans Londonderry Selectboard Londonderry Road Foreman Londonderry Resident Windham Regional Commission 3 of 48

4 Office of Highway Safety Road Safety Audit Review Information Reviewed Geometry Main Street is located in the village of South Londonderry and runs along the West River. It becomes Thompsonburg Road north of Rowes Road as the land use characteristics become more rural. Thompsonburg Road is a winding road with several horizontal curves that follow the Tannery Brook. There are steep drop-offs along both the West River and the Tannery Brook. This is a two-lane road with an approximate twenty-two-foot road surface. At the time of the site visit, there was a yellow center line on the entire length of the road with the exception of the portion that had been paved in June. In the principal area of interest, Town Highway 2 is intersected four times by four different town highways (Rowes Road, Cross Road, Carley Lane and Under Mountain Road). All of these intersections are three-way intersections. The intersection with Cross Road and the one with Under Mountain Road are controlled by a stop sign on the side roads. The other two intersections have not traffic control. Thompsonburg Road intersects VT 11 at its northern terminal. This is a three-way intersection with a stop sign located on the Thompsonburg approach. Speed Limit There is currently no posted speed limit on Town Highway 2. As such, per 23 V.S.A. 1081, the speed limit is assumed to be 50 mph. The Windham Regional Commission conducted speed studies at different locations on Town Highway 2 on July 2018 and September The results of these studies are displayed in the next table. As can be seen from this table, north of Carley Lane, the average speed was measured to be 43 mph while the 85 th percentile speed was determined to be around 48 mph and 49 mph (meaning that 85% of the traffic travels at a speed of mph or less). South of Old School Road on Main street, the 85 th percentile was measured at 42 mph. 4 of 48

5 Office of Highway Safety Road Safety Audit Review Site # Location Date ft south of Under the Mountain Road 500 ft north of Carley Lane 400 ft north of Cross Road Main St, ¼ mile south of Old School Road 7/11/18 7/17/18 7/11/18 7/17/18 Avg Speed 85th Percentile % above 50 mph Daily Traffic 43 mph 49 mph 13.6% mph 48 mph 7.4% 615 9/5/18 9/11/18 37 mph 42 mph 0.7% 850 Traffic Volumes & Bike Count The 2018 Average Annual Daily Traffic (AADT) just north of Carley Lane was 615 vehicles per day. The AADT at this location has not changed considerably over the last decade as illustrated by the next graph. Average Annual Daily Traffic (just north of Carley Ln) of 48

6 Office of Highway Safety Road Safety Audit Review Shown below is an example of the daily distribution of traffic just north of Carley Lane (taken from the May 27 to May 28, 2013 study). This typical traffic distribution shows that traffic is heavier between 11:00 am and 1:00 pm (13:00) with 60 to 70 vehicles per hour. 80 Daily Distribution, Vehicles per Hour (just north of Carley Ln) The Windham Regional Commission installed a bike counter for a one-week period from September 4 to September 12, The graph below shows the bike traffic by day of the week for the survey period. The daily average number of bikes per day was 9 bicycles per day. The maximum number of bicycles during the study period was 13 and occurred on Saturday September 8. 6 of 48

7 Office of Highway Safety Road Safety Audit Review Pavement Condition The pavement surface condition between Old School Street and Cross Road is very good as this portion of Town Highway 2 was paved this summer. The condition of the segment that extends from Cross Road to VT 11 is in poor condition based on visual inspection as evidenced in the picture below. 7 of 48

8 Office of Highway Safety Road Safety Audit Review Past Projects Town Highway 2 was resurfaced between Old School Street and Cross Road in June Future Projects As per the information obtained during the site visit, the Town has plans to pave the reminder of Town Highway 2 up to VT 11. This may happen in about two years as there is at least one other road that has a greater priority. Crash History The crash data along Town Highway 2 between Rowes Road and VT 11 for the 2010 up to the time of the road safety audit site visit (August 21, 2018) was reviewed. A collision diagram is available in Appendix A. It was found that a total of seven crashes had taken place during this period. It was also found that these crashes happened between Rowes Road and Carley Lane with a cluster of crashes in the area of the long sweeping curve that is located below Carley Lane and just above Cross Road. Most of these crashes were related to a vehicle losing control. Many of them were single vehicle crashes. In two cases, a vehicle fell into the river. Snowy or icy conditions were present in three of the crashes. With the exception of one crash, all crashes took place between the months of December and March. The graph below shows that crashes are occurring in the earlier hours of the day. 8 of 48

9 Office of Highway Safety Road Safety Audit Review Crashes Crashes by Time of Day :00 1:00 1:00 2:00 2:00 3:00 3:00 4:00 4:00 5:00 5:00 6:00 6:00 7:00 7:00 8:00 8:00 9:00 9:00 10:00 10:00 11:00 11:00 12:00 12:00 13:00 13:00 14:00 14:00 15:00 15:00 16:00 16:00 17:00 17:00 18:00 18:00 19:00 19:00 20:00 20:00 21:00 21:00 22:00 22:00 23:00 23:00 24:00 Crashes were also reviewed for the intersection of Thompsonburg Road and VT 11. There have been four crashes reported at this intersection since 2010 (one in 2011, one in 2014, one in 2015 and one in 2016). While there is no record in the state crash repository, the property owner of the house (4323 Route VT 11) across Thompsonburg Road told the audit team that there had been a recent crash at this intersection in August Of the four crashes reported, three crashes involved vehicles that went off the road while traveling westbound on VT 11. In one case, the driver swerved to avoid a vehicle that was waiting to make a left turn onto Thompsonburg Road. In the other two cases, one driver fell asleep and one was driving under the influence. All three vehicles left the north side of VT 11 near the 4323 Route VT 11 property. The other single vehicle crash involved a motorcycle driver who was traveling north on Thompsonburg Road and who lost control of his bike as he took the turn onto VT 11 too wide. Current Local Concerns The Town reported the following: 9 of 48

10 Office of Highway Safety Road Safety Audit Review Thompsonburg Road is one of the most heavily travelled roads in the town, and is also a popular byway for walkers, runners, cyclists, and is frequently used by students from the Stratton Mountain School for dryland XC ski training. Thompsonburg Road provides a shortened route between South Londonderry and Route 11 east of the town. There are numerous safety issues along the road: o Narrow lanes of travel with no shoulder o Sharp curves that are poorly warned or not warned at all o Poor sightlines on some of the curves o Abrupt drop-offs into the West River and Tannery Brook, with no guardrails o Hazardous egress onto Route 11, specifically when turning to travel west o Perception that there has been an increase in unsafe travel speeds There are no drainage issues along Thompsonburg Road but shade on the road way causes the road surface to freeze at times and this has been the biggest maintenance problem. The intersection with VT 11 pauses a problem for those who are traveling westbound waiting to make a left turn onto Thompsonburg Road as VT 11 westbound traffic (especially trucks) is traveling at a high rate of speed. Identified Safety Concerns This section lists the areas of safety concern identified by the audit team during the site inspection and from the analysis of available data. This section also reports the potential safety enhancements suggested by the audit team. The concerns are not listed in order of importance. Concern: Potential of Losing the Control of a Vehicle around the Horizontal Curves A typical crash pattern on Town Highway 2 corresponds to roadway departure crashes. Historically, this type of crashes mostly happened at a horizontal curve. 10 of 48

11 Office of Highway Safety Road Safety Audit Review The usual safety enhancements related to roadway departure crashes at horizontal curves include enhancements that Keep the Vehicle on the Road (KVR), that Reduce the Potential for a Crash (RPC) or that Minimize the Severity of a Crash (MSC). Safety Enhancements: Immediate Action 1, KVR. Review the horizontal curves along this road and determine the appropriate advisory speed for each curve in each direction and what type of signage each curve should have. Action 2, KVR. Contact the District to have the double yellow centerline repainted where the road was recently paved. Immediate to Short Term Action 3, RPC. Improve the sight lines around certain curves by removing brush and trees as shown in Appendix B. Short to Mid Term Action 4, KVR. Improve delineation at each curve as appropriate by installing the warning signs identified in Action 1 (See Appendix C). Action 5, KVR. Improve delineation by installing white edgeline pavement markings. Mid to Long Term Action 6, RPC. Consider the installation of the Safety Edge as part of the next paving project on this road (See Appendix D). Action 7, RPC. Consider the widening of the road on the outside of critical curves (curves with an advisory speed of 30 mph or less). Action 8, SVC. Remove the large trees that are shown in Appendix B to reduce the severity of a potential crash. 11 of 48

12 Office of Highway Safety Road Safety Audit Review Action 9, SVC. Install guardrail at certain curves to prevent vehicles from falling into the Tannery Brook (See Appendix E). Concern: There are some Steep Drop-offs along the River or the Brook that are Unprotected and that Could Pause a Risk to Motorists Safety Enhancements: Mid to Long Term Action 10, Consider installing guardrail at certain locations to prevent vehicles from potentially falling into the Tannery Brook or the West River (See Appendix E). Concern: Motorists are Perceived to Be Traveling Too Fast for the Characteristics and Usage of the Road Safety Enhancements: Short to Mid Term Action 11. Consider setting speed limits for this road. From the speed studies done by WRC and based on the Manual on Uniform Traffic Control Devices, the speed limits shown in the following table are suggested. Suggested locations for speed limit signs are shown in Appendix C. The Town will need to adopt a speed ordinance to set these suggested speed limit. 12 of 48

13 Office of Highway Safety Road Safety Audit Review From To Measured 85th Percentile Recommended Speed Limit VT 100 Approx., 500 ft north of VT100 Approx., 135 ft north of Rowes Road Approx., 500 ft north of VT100 Approx., 135 ft north of Rowes Road VT mph 1 42 mph 35 mph 48 mph 45 mph Action 12. Improve delineation at each curve as appropriate by installing the warning signs and advisory speeds identified in Action 1 (See Appendix C). Action 13. Reduce the width of the travel lanes by installing white edgeline markings. Concern: Lack of Conspicuity of the Bridge South of the Power Station The bridge south of the power station is somewhat narrow. While it is delineated with object markers, these signs are old (and one is missing). In addition, brush is covering some parts of the guardrail and some of the object markers. Safety Enhancements: Immediate Action 14. Remove the brush along the guardrail and the object markers (See Appendix B). Short to Mid Term Action 15. Install four new object markers and a Narrow Bridge warning sign for each direction (See Appendix C). 1 Suggested based on the character of the area 13 of 48

14 Office of Highway Safety Road Safety Audit Review Concern: Non-Uniform Installation of the Stop Sign at Under Mountain Road The stop sign at Under Mountain Road is located across Thompsonburg Road. The location of this stop sign across the main road violates drivers expectation since the conventional location for a stop sign is on the right-hand side of the approach. There is the potential for a motorist to drive across Thompsonburg Road to the existing stop sign and getting hit by an oncoming vehicle. Safety Enhancements: Action 16 Relocate the stop sign to the right-hand side of the Under Mountain Road approach (See Appendix C). Short to Mid Term Action 17. Install a Double Arrow assembly across Under Mountain Road to improve the detection of the end of Under Mountain road by motorists (See Appendix C). Concern: Potential for Rear-End Crashes or Evasive Maneuvers on VT 11 Westbound at the intersection with Thompsonburg Road. The horizontal curve on VT 11 and the brush on the north side of VT 11 reduce the available stopping sight distance for traffic traveling westbound on VT 11 and approaching the Thompsonburg Road intersection. Due to the downhill grade on VT 11, traffic and especially semi-trailer trucks, are traveling at a fast rate. In addition, there is little warning of the intersection and unfamiliar drivers wanting to turn left off Route 11 are suddenly coming upon the side road without much warning and could be surprised and forced to brake quickly. Because of these issues, there is the potential for westbound vehicles to rear-end a vehicle that is waiting to turn left or making a sudden left turn onto Thompsonburg Road or the potential for 14 of 48

15 Office of Highway Safety Road Safety Audit Review westbound vehicles to try to swerve around these left turning vehicles to avoid a collision and subsequently go off the road. Using the video log, it was estimated that the available stopping sight distance to stop in time when there is only one vehicle stopped waiting to turn left was about 565 feet. This value is above what is recommended by the American Association of State Highway and Transportation Officials ( AASHTO Green Book ) for a speed of 55 mph on a 6% downgrade (553 feet) but less than what is recommend for 60 mph on a 6% downgrade (638 feet). Per data obtained from the ARAN Van, the downgrade on VT 11 is 5.17%. Safety Enhancements: Short Term Action 18. Install an advance side road warning sign (W2-2) for westbound traffic. Action 19. Install a 12-inch high Thompsonburg Road street name sign (6 inch capital and 4-1/2 inch lower case letters) on separate posts (not in combination with the stop sign) and closer to the intersection so that it is more visible by motorists on VT 11.Action 20. Improve the stopping sight distance by removing as much brush and trees as possible around the inside of the curve on VT 11. The pictures below, while from 2016, are illustrative of what could be removed. 15 of 48

16 Office of Highway Safety Road Safety Audit Review Looking westbound on VT 11. Source: Mapillary 16 of 48

17 Office of Highway Safety Road Safety Audit Review Looking westbound on VT 11 closer to the intersection. Source: Mapillary 17 of 48

18 Office of Highway Safety Road Safety Audit Review Summary of Safety Enhancements The safety concerns and potential actions that were identified in the previous sections are further summarized in the next table. These potential enhancements will be presented to respective parties for further consideration. The entities listed under the column called Potential Responsibility are suggested groups that could possibly implement some of the countermeasures. In this table, time frames and costs are qualified as follows: short term, < 1 year; mid-term 1-3 years; long term > 3 years; low cost, < $15,000; medium cost, $15,001 - $75,000; high cost, > $ 75,001. The safety concerns discussed previously are referred to in the table by the numbers shown here: 1. Potential of losing the control of a vehicle around the horizontal curves, 2. There are some steep drop-offs along the river or the brook that are unprotected and that could pause a risk to motorists, 3. Motorists are perceived to be traveling too fast for the characteristics and usage of the road, 4. Lack of conspicuity of the bridge south of the power station, 5. Non-uniform installation of the stop sign at Under Mountain road, 6. Potential for rear-end crashes or evasive maneuvers on VT 11 westbound at the intersection with Thompsonburg Road. 18 of 48

19 Potential Safety Enhancements Summary Table Safety Concerns Potential Responsibility Safety Payoff 2 Time Frame Cost Safety Enhancement Review the horizontal curves to determine the appropriate advisory speed Contact the District to have the double yellow centerline repainted Improve the sight lines around certain curves by removing brush and trees X X VTrans Office of Highway Safety Done 9/7/18 X Town Now Low X Town Now to Short Low Low to Med 2 The CMF Clearinghouse explains that the star quality rating indicates the quality or confidence in the results of the study producing the CMF. The star rating is based on a scale (1 to 5), where a 5 indicates the highest or most reliable rating. The review process considers five categories for each study: study design, sample size, standard error, potential bias, and data source. 19 of 48

20 Potential Safety Enhancements Summary Table Safety Concerns Potential Responsibility Safety Payoff 2 Time Frame Cost Safety Enhancement Improve delineation at each curve by installing the warning signs identified in the curve review X X Town 37% reduction in all crashes (CMF ID 1898, 3 stars) Short to Mid Low Install white edgeline pavement markings X X Town 15% reduction in all crashes (CMF ID 5646, 3 stars) Short to Mid Low to Med Consider the installation of the Safety Edge with the next paving project X Town 10.8% reduction in all crashes (CMF ID 9660, 5 stars) Mid to Long Low to Med Consider the widening of the road on the outside of critical curves X Town Mid to Long High 20 of 48

21 Potential Safety Enhancements Summary Table Safety Concerns Potential Responsibility Safety Payoff 2 Time Frame Cost Safety Enhancement Remove the identified large trees to reduce the severity of a potential crash X Town Varies from 11% to 77%, depending on before/after tree line 3 Mid to Long Low Install guardrail X X Town Mid to Long Mid to High Consider setting speed limits Remove the brush along the guardrail and the object markers X Town 6% reduction in all crashes from 50 mph to 45 mph (CMF ID 8204, 3 stars) Short to Mid X Town Now Low Low 3 NCHRP 500 Report, Volume 3, Appendix 8 21 of 48

22 Potential Safety Enhancements Summary Table Safety Concerns Potential Responsibility Safety Payoff 2 Time Frame Cost Safety Enhancement Install four new object markers and a Narrow Bridge warning sign for each direction Relocate the stop sign to the right-hand side of the Under Mountain Rd approach Install a Double Arrow assembly across Under Mountain Road Install an advance side road warning sign (W2-2) for WB traffic X Town Short to Mid Low X Town Now Low X Town X Pavement Management via project STP PS 19(10) Short to Mid Short to Mid Low Low 22 of 48

23 Potential Safety Enhancements Summary Table Safety Concerns Potential Responsibility Safety Payoff 2 Time Frame Cost Safety Enhancement Install a 12- inch high Thompsonburg Road street name sign (6 inch capital and 4-1/2 inch lower case letters) on separate posts closer to the intersection X Pavement Management via project STP PS 19(10) Short to Mid Low Remove as much brush and trees as possible around the inside of the curve on VT 11 X VTrans District 2 or Pavement Management via project STP PS 19(10) Now to Short Low to Med 23 of 48

24 Appendix A Collision Diagrams 24 of 48

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26 Crash # Case # Crash Date Time Weather Contributing Circumstances Direction of Collision # Injuries # Fatalities Approximate Location 1 11D /5/2011 9:19 AM Clear Single Vehicle Crash 0 0 Thompsonburg Road at Doe Lane 2 11D /8/2011 6:47 AM Snow Driving too fast for conditions Single Vehicle Crash 0 0 Thompsonburg Road at Cross Road TH# D /16/2013 2:36 AM [No Weather] [No Direction of Collision] 0 0 TH 2 THOMPSONBURG RD at Carly Rd 4 13D /17/2013 8:15 PM Clear 5 13D /23/2013 2:10 AM Clear 6 14D /18/2014 2:27 PM Snow Operating defective equipment Single Vehicle Crash 0 0 [No Street Address] at Old School St Fatigued asleep Failure to keep in proper lane Single Vehicle Crash 1 0 Thompsonburg Rd at Carley Lane Failure to keep in proper lane No improper driving Opp Direction Sideswipe 1 0 Thompsonburg Rd at Cross Rd 7 16D /20/2016 6:48 AM [No Weather] Rear End 0 0 Thompsonburg Rd at Cross Rd 8 16D /4/2016 6:31 PM Clear Failure to keep in proper lane Single Vehicle Crash 1 0 Thompsonburg Rd 26 of 48

27 VT 11 and Thompsonburg Road Intersection ( ) No Data Available for 2018 Crash # Case # Crash Date Time Weather Contributing Circumstances Direction of Collision # Injuries # Fatalities 1 14D /07/ :17 Clear Failure to keep in proper Single Vehicle Crash 0 0 lane, Under the influence of medication/drugs/alcohol 2 13D /23/ :44 Cloudy Failure to keep in proper lane Single Vehicle Crash D /24/ :28 [No Weather] [No Direction of Collision] D /25/ :29 Clear Inattention Single Vehicle Crash D /19/ :36 Clear Failure to keep in proper lane, Under the Single Vehicle Crash of 48

28 Appendix B Brush/Tree Clearing 28 of 48

29 Traveling Northbound Removal of Brush/Trees to Improve Sight Lines X X Removal of Trees to Reduce Severity 29 of 48

30 Removal of Brush to Make the Bridge more Visible Removal of Brush to Make the Bridge more Visible 30 of 48

31 Traveling Southbound Removal of Brush/Trees to Improve Sight Lines Removal of Brush to Make the Bridge more Visible 31 of 48

32 X X Removal of Brush/Trees to Improve Sight Lines Removal of Trees to Reduce Severity (same as in NB direction) X Removal of Tree to Reduce Severity 32 of 48

33 Removal of Brush/Trees to Improve Sight Lines 33 of 48

34 Appendix C Proposed Signage 34 of 48

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41 Appendix D Safety Edge Information 41 of 48

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46 VTrans Details: Link, HSD Safety Edge Details Example of Request for Paving Bids 46 of 48

47 Appendix E Proposed Guardrail Locations 47 of 48

48 Mile Points to (Using the mile point system shown on the sign layout). Area where motorists have fallen into the river Mile Points to (Using the mile point system shown on the sign layout). Area of Getty Station to just before Rowes Rd 48 of 48