BENNING ROAD & BRIDGES TRANSPORTATION IMPROVEMENTS CRASH DATA AND SAFETY ANALYSIS TECHNICAL MEMORANDUM DRAFT MAY 2016
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Table of Contents 1.0 Introduction... 1 1.1 Crash Data for Key Intersections... 1 2.0 Relation of Build Alternative Alignments to Key Intersections... 4 3.0 Intersection Collision Diagrams and Detailed Analysis of Collisions... 5 3.1 Benning Road and Minnesota Avenue Intersection... 5 3.2 Benning Road and East Capitol Street Intersection... 7 3.3 Minnesota Avenue and Nannie Helen Burroughs (NHB) Avenue Intersection... 8 3.4 Benning Road and 36 th Street Intersection... 9 3.5 Benning Road and Anacostia Avenue Intersection... 10 3.6 Benning Road and 34 th Street Intersection... 11 3.7 Benning Road and 45 th Street Intersection... 12 3.8 Benning Road and Central Avenue Intersection... 13 3.9 Minnesota Avenue and Dix Street Intersection... 14 3.10 Minnesota Avenue and Grant Street Intersection... 15 3.11 Minnesota Avenue and Hayes Street Intersection... 16 3.12 Minnesota Avenue and Gault Place Intersection... 17 APPENDIX A-i
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1.0 Introduction This crash data and safety analysis technical memorandum identifies existing safety problems along the project corridor. The analysis provides crash data for the study intersections in order to evaluate safety conditions and identify factors contributing to collisions. The analysis is based on data provided by the District Department of Transportation (DDOT) spanning the period from 2011 through 2013 from DDOT s Traffic Accident Reporting and Analysis System. Note that no crash data was available at Benning Road and Oklahoma Avenue, Benning Road and 42 nd Street, and Benning Road and 44 th Street intersections, and thus not included in the analysis. 1.1 Crash Data for Key Intersections Crash data was provided for twelve key intersections within the study area. The crash data includes type of crashes (e.g., rear end, side swiped), crash severity (e.g., injuries involved), the crash location, and also indicates whether any pedestrians were involved in the accident. The crash data analysis was performed in two steps. The first step calculated the crash rate at the study intersections and provided a summary of crash data statistics at an intersection level. The second step developed collision diagrams (i.e., visual representation of crashes) at every intersection to identify potential problem areas and safety deficiencies at intersections. Crash rate for intersections is expressed as crashes per million entering vehicles (MEV), and is calculated as follows: RRRRRRRR = (CC 1,000,000)/(nn 365 VV) where C is the total number of intersection-related crashes (also known as crash frequency) in the study period, n is the number of years data (i.e., analysis period), and V is the daily traffic volumes entering the intersection. Daily traffic volumes were calculated using the peak-hour traffic volumes entering the intersection and a peak hour factor of daily volumes calculated based on the historic annual average daily traffic (AADT) data. Because crash data includes crashes occurred between 2011 and 2013, Peak-hour traffic volumes from the Feasibility Study were used in the analysis because crash data provided occurred between 2011 and 2013. The summary of crash rate at the study intersections is provided in Figure 1. Table 1 provides detailed statistics about crash data. APPENDIX A-1
Principal observations from Figure 1 and Table 1 include: Just over half (7) of the 12 key crash intersections in the study area are located along Benning Road, which is the project corridor for the two Build Alternatives. The highest crash rate location is at Benning Road and Minnesota Avenue with an MEV of 2.48. The second highest crash rate location is at Benning Road and East Capitol Street with an MEV of 1.51. The third highest crash rate location is at Minnesota Avenue and Nannie Helen Burroughs Avenue with an MEV of 1.39. The annual average for the number of crashes for the 12 key intersections from 2011 to 2013 was 129, while the annual average for crashes resulting in injury was 50. Figure 1: Benning Road and Minnesota Avenue Crash Diagram A-2 APPENDIX
Table 1: Crash Data Summary at the Study Intersections Intersection Benning Rd and Anacostia Ave Benning Rd and 34 th St Benning Rd and 36 th St Benning Rd and Minnesota Ave Benning Rd and 45 th St Benning Rd and Central Ave Benning Rd and East Capitol St Number of Crashes Crash Rate (MEV) Rear-end Sideswipe Right Angle Collision Type (2011-2013) Head on Left Turn Hit Veh Left Turn Hit Ped Right Turn Hit Veh Right Turn Hit Ped Straight Hit Ped Crashes Resulting in Injury 23 0.46 52% 17% 17% 4% 12 16 0.31 19% 25% 6% 6% 19% 13% 9 26 0.74 46% 31% 4% 4% 8% 14 120 2.48 28% 31% 4% 3% 12% 1% 7% 4% 5% 38 12 0.49 25% 42% 8% 8% 8% 4 10 0.43 30% 40% 10% 10% 10% 3 90 1.51 26% 27% 8% 4% 6% 9% 2% 7% 32 Minnesota Ave and Dix St 16 0.64 44% 0% 6% 19% 13% 6% 9 Minnesota Ave and Grant St 16 0.72 44% 19% 13% 7 Minnesota Ave and Hayes St 2 0.11 50% 50% 0 Minnesota Ave and Gault Pl 6 0.32 17% 50% 17% 1 Minnesota Ave and NHB Ave 49 1.39 35% 27% 12% 6% 6% 6% 22 APPENDIX A-3
2.0 Relation of Build Alternative Alignments to Key Intersections Table 2 lists the 12 key intersections, and show which intersections are located along or in close proximity to each of the two Build Alternative alignments. This table also identifies intersections (with an *) that are near to a potential station. Overall, the table shows that six key intersections are closely associated with both Build Alternatives. Table 2: High Crash Intersections Along the Build Alternatives Intersection Build Alternative 1 Build Alternative 2 Benning Rd and Anacostia Ave X X Benning Rd and 34 th St X* X* Benning Rd and 36 th St X X Benning Rd and Minnesota Ave X X Benning Rd and 45 th St X X Benning Rd and Central Ave Benning Rd and East Capitol St X* X* Minnesota Ave and Dix St Minnesota Ave and Grant St Minnesota Ave and Hayes St Minnesota Ave and Gault Pl Minnesota Ave and NHB Ave *Denotes potential station at intersection. A-4 APPENDIX
3.0 Intersection Collision Diagrams and Detailed Analysis of Collisions This section displays collision diagrams for each intersection and provides a brief discussion for the potential causes of crashes. Collision diagrams are prepared to understand the crash pattern, safety problem and also deficiency of the intersection operation. Note that collision discussion is provided only at intersections and approaches for high frequency of crashes. 3.1 Benning Road and Minnesota Avenue Intersection Figure 2 and Table 3 provide crash analysis information for the Benning Road and Minnesota Avenue intersection. Figure 2: Benning Road and Minnesota Avenue Crash Diagram APPENDIX A-5
Table 3: Potential Causes of Crashes at Benning Road and Minnesota Avenue Intersection Movement Collision Type Potential Causes of Crashes Speeding (Downhill approach) Stop and go traffic due to peak hour congestion Eastbound left turn queue spillover due to heavy left turn volume Eastbound Benning Inadequate green time Road Westbound Benning Road Northbound Minnesota Avenue Southbound Minnesota Avenue Right Turn Hit Pedestrians Left Turn Hit Pedestrians Protected and permissive phasing Not adequate green time during the protected phase leading to more aggressive gap acceptance during the permitted phase Location of crosswalk (not at the tangent point) Permissive only left turn phasing Only permissive phase is permitted Heavy opposing through traffic causing more aggressive gap acceptance Heavy pedestrian volumes crossing the intersection on the south side of the intersection Stop and go traffic due to peak hour congestion Speeding and more aggressive behavior due to cycle overflows (i.e., queue cannot clear the intersection in the current cycle) Inadequate storage lane, causing queue spillover and lane change for the through vehicles A-6 APPENDIX
3.2 Benning Road and East Capitol Street Intersection Figure 3 and Table 4 provide crash analysis information for the Benning Road and East Capitol Street intersection. Figure 3: Benning Road and East Capitol Street Crash Diagram East Capitol St and Benning Rd NE N Table 4: Potential Causes of Crashes at Benning Road and East Capitol Street Intersection Movement Collision Type Potential Causes of Crashes Northbound Benning Road Inadequate storage space for northbound left turn traffic Heavy left turn volume in the morning peak hour (450 vehicles) Split phasing, which may cause lane changes during queue clearance Stop and go traffic due to peak hour congestion Speeding and more aggressive behavior due to cycle overflows (i.e., queue cannot clear the intersection in the current cycle) Eastbound East Stop and go traffic due to peak hour congestion Capitol Street Speeding and more aggressive behavior due to cycle overflows (i.e., queue cannot clear the intersection in the current cycle) APPENDIX A-7
3.3 Minnesota Avenue and Nannie Helen Burroughs (NHB) Avenue Intersection Figure 4 and Table 5 provide crash analysis information for the Minnesota Avenue and Nannie Helen Burroughs (NHB) Avenue intersection. Figure 4: Minnesota Avenue and Nannie Helen Burroughs Avenue Crash Diagram Minnesota Ave and NHB Ave NE N A-8 APPENDIX
Table 5: Potential Causes of Crashes at Minnesota Avenue and Nannie Helen Burroughs Avenue Intersection Movement Collision Type Potential Causes of Crashes Eastbound Nannie Helen Burroughs Avenue Northbound Minnesota Avenue 3.4 Benning Road and 36 th Street Intersection Visibility issues due to the existing bridge Left turn is shared with through (also lagging left turn), which may cause sudden stops (sideswiped collisions can also be attributed to shared left turn operation) Stop and go traffic due to peak hour congestion Speeding and more aggressive behavior due to cycle overflows (i.e., queue cannot clear the intersection in the current cycle) Figure 5 and Table 6 provide crash analysis information for the Benning Road and 36 th Street intersection. Figure 5: Benning Road and 36 th Street Crash Diagram Benning Rd and 36 th St NE N APPENDIX A-9
Table 6: Potential Causes of Crashes at Benning Road and 36 th Street Intersection Movement Collision Type Potential Causes of Crashes Eastbound Benning Road Lack of proper signage for the off-ramp Lane change and slowing down to get onto off-ramp Westbound Benning Road Possible conflict with merging traffic (might have also caused sideswiped collisions) 3.5 Benning Road and Anacostia Avenue Intersection Figure 6 provides crash analysis information for the Benning Road and Anacostia Avenue intersection. No high frequency of crashes is present at the intersection. Figure 6: Benning Road and Anacostia Avenue Crash Diagram Benning Rd and Anacostia Ave NE N A-10 APPENDIX
3.6 Benning Road and 34 th Street Intersection Figure 7 provides crash analysis information for the Benning Road and 34 th Street intersection. No high frequency of crashes is present at the intersection. Figure 7: Benning Road and 34th Street Crash Diagram Benning Rd and 34 th St NE N APPENDIX A-11
3.7 Benning Road and 45 th Street Intersection Figure 8 provides crash analysis information for the Benning Road and 45 th Street intersection. No high frequency of crashes is present at the intersection. Figure 8: Benning Road and 45 th Street Crash Diagram Benning Rd and 45 th St NE N A-12 APPENDIX
3.8 Benning Road and Central Avenue Intersection Figure 9 provides crash analysis information for the Benning Road and Central Avenue intersection. No high frequency of crashes is present at the intersection. Figure 9: Benning Road and Central Avenue Crash Diagram Benning Rd and Central Ave NE N APPENDIX A-13
3.9 Minnesota Avenue and Dix Street Intersection Figure 10 provides crash analysis information for the Minnesota Avenue and Dix Street intersection. No high frequency of crashes is present at the intersection. Figure 10: Minnesota Avenue and Dix Street Crash Diagram Minnesota Ave and Dix Rd NE N A-14 APPENDIX
3.10 Minnesota Avenue and Grant Street Intersection Figure 11 provides crash analysis information for the Minnesota Avenue and Grant Street intersection. No high frequency of crashes is present at the intersection. Figure 11: Minnesota Avenue and Grant Street Crash Diagram Minnesota Ave and Grant St NE N APPENDIX A-15
3.11 Minnesota Avenue and Hayes Street Intersection Figure 12 provides crash analysis information for the Minnesota Avenue and Hayes Street intersection. No high frequency of crashes is present at the intersection. Figure 12: Minnesota Avenue and Hayes Street Crash Diagram Minnesota Ave and Hayes St NE N A-16 APPENDIX
3.12 Minnesota Avenue and Gault Place Intersection Figure 13 provides crash analysis information for the Minnesota Avenue and Gault Place intersection. No high frequency of crashes is present at the intersection. Figure 13: Minnesota Avenue and Gault Place Crash Diagram Minnesota Ave and Gault Pl NE N APPENDIX A-17
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