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Road Safety Audit Blair Road/Cedar Road/4 th Street Intersection PowerPoint Presentation
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Road Safety Audit Blair Road/Cedar Road/4 th Street Intersection

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Road Safety Audit Blair Road/Cedar Road/4 th Street Intersection

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Road Safety Audit Blair Road/Cedar Road/4 th Street Intersection

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  1. Road Safety AuditBlair Road/Cedar Road/4th Street Intersection DDOT Transportation Safety Team

  2. RSA Team Background Purpose & Need Formal safety performance examination of roadway or intersection by an independent, multidisciplinary road safety audit (RSA) team It qualitatively estimates and reports on potential road safety issues and identifies opportunities for improvements in safety for all road users Blair Rd/Cedar St/4th St intersection identified by District as a safety problem location RSA team would identify safety issues at this location and suggest countermeasures for improvements in safety Road Safety Audity (RSA) Team DDOT - Safety, Signals, IPMA, PPSA, PTSA, Bike & Peds, Parking, Street lighting, NHTSA and UFA USDOT - FHWA MPD WMATA FEMA

  3. We are here Road Safety Audit Procedure

  4. Accident Analysis 3-year accident analysis Total 24 accidents from 2008-2010 11 out of 24 accidents (50%) resulted in injuries 4 out of 24 accidents (20%) resulted in disabling injuries Blair/Cedar – 15 accidents (60%) 4th/Cedar – 7 accidents (30%) Blair/4th – 2 accidents (10%)

  5. Observations Following issues affect traffic and pedestrian safety at intersection • Complex intersection geometry and traffic control; • Significant pedestrian-vehicle conflicts; • High accident frequency; • Insufficient traffic signage; • Faded pavement markings

  6. Traffic Analysis – Existing Conditions • Estimated 2010 Average Daily Traffic Volumes • Blair Rd – 15000 vehicles • Cedar St – 5300 vehicles • 4th St – 1600 vehicles • Speed study shows 32 mph speed on Blair Rd which is significantly higher than posted 25 mph speed limit • Existing level of service (LOS) analysis at 21 intersections along Blair Rd, Piney Branch Rd, Aspen St, Butternut St and Cedar St • Blair Rd/4th St/Cedar St intersection operates at: • LOS E during AM peak-hour • LOS F during PM peak-hour

  7. Traffic Analysis – Existing Conditions • Blair Rd intersection at Piney Branch Rd operates at LOS E during AM peak-hour • Remaining study intersections operate at LOS D or better during both AM and PM peak-hour

  8. Proposed Alternatives

  9. Signal Phasing Improvements in Alternative #2 Split phasing on Blair Rd with overlap for WB right-turns • At the beginning of cycle: • SB vehicles receive ROW at beginning of cycle • WB right-turns simultaneously maneuver on overlap phase. • West X-walk concurrently receives walk interval • NB vehicles receive ROW after termination of SB phase • NB left-turns are NOT allowed • East X-walk concurrently receives walk interval • West X-walk continues to receive walk interval • WB left-turns and thru traffic receive ROW after termination of NB phase • “No Turn on Red” prohibition for WB right-turns • North X-walk on Blair Rd concurrently receives walk interval

  10. Signal Phasing Improvements in Alternative #2 Split phasing on Blair Rd with overlap for WB right-turns • EB traffic receives ROW after termination of leading left-turn phase on WB • EB left-turns not allowed • “No Turn on Red” prohibition for WB right-turns • EB right-turns and WB left-turns maneuver on permissive phasing • South X-walk concurrently receives walk interval • North X-walk continues to receive walk interval

  11. Signal Phasing Improvements in Alternative #2 Primary Advantages • No conflicts for pedestrians in North X-walk • WB right-turns only allowed on overlap phase • “No Turn on Red” prohibition for WB right-turns • EB left-turns not allowed • Eliminates SB left-turn conflicts with pedestrians in East X-walk • Exclusive ROW for NB and SB vehicles on Blair Rd • Concurrent walk interval with NB traffic only

  12. Traffic Analysis – Future Conditions • Roadway improvement under first and third alternatives cause: • Significant diversion of existing travel patterns • Significant increase in traffic volumes on Aspen St, Butternut St & Cedar St • Considerable traffic calming and pedestrian safety issues in residential neighborhoods • Do not propose signal phasing improvements to reduce pedestrian accidents • Roadway and signal phasing improvements under second alternative: • Do not cause significant diversion of existing travel patterns • Improve intersection level of service • Enhance sight distance and pedestrian visibility • Eliminate critical pedestrian-vehicle conflicts • Therefore, RSA team recommends Second Alternative

  13. Conceptual Design for Alternative #2

  14. Safety Issue #1 - Complex Intersection Geometry and Traffic ControlSkewed Intersection Geometry • Vehicles on 4th/Blair travel • in “snake pattern” due to • the minor offsets • Horizontal & vertical • alignments don’t provide • easy access for bikes and • pedestrians • No pedestrian signal for • X-walk on 4th St • Upgrade all pedestrian • facilities to meet new • ADA specifications • Multiple curb cuts impact • traffic movements and • pedestrian access • 5 leg intersection has skewed geometry • 4th St intersects Blair Rd at sharp angle • 4th St and Blair Rd have minor offsets • south of the intersection • 4th St serves as an outlet for cut-through • traffic that wants to circumvent queuing • on Blair Rd

  15. Safety Issue #1 - Complex Intersection Geometry and Traffic ControlComplex Traffic Control • SB thru vehicles cut across • west X-walk on Cedar St • to circumvent SBLT that • block the intersection • Direct conflict with the • pedestrians on west • crosswalk on Cedar St • Multiple traffic signals • for 4th St and Blair Rd • Motorists confused in • deciding • - when to leave the • intersection; and • - who has pertinent • right-of-way • SB left-turns (SBLT) on Blair Rd block • intersection and also run red light • Direct conflict with opposing vehicles • on 4th St and Cedar St • Conflict with pedestrians in X-walks on • both Blair Rd and Cedar St • Above photo shows 4 SB left-turns on • Blair Rd blocking intersection and • jumping red light

  16. Safety Issue #1 - Complex Intersection Geometry and Traffic ControlInadequate Sight Distance Vehicles on 4th St cannot see pedestrians in X-walks on Cedar St WB right-turns on Cedar St cannot see pedestrians in North X-walk on Blair Rd

  17. Safety Issue #1 - Complex Intersection Geometry and Traffic ControlInadequate Sight Distance Vehicles on NB Blair Road cannot see pedestrians in X-walks on Cedar St Vehicles on SB Blair Road cannot see pedestrians in east X-walks on Cedar St

  18. Solutions for Safety Issue #1 • Relocation of east X-walk on Cedar St and south X-walk on Blair Rd would significantly improve visibility of pedestrians in: • East X-walk on Cedar St for SB left-turns on Blair Rd • North X-walk on Blair Rd for WB right-turns on Cedar St • East and west X-walks on Cedar for NB vehicles on Blair Rd • Split phasing with right-turn overlap operations would: • Eliminate SB left-turn conflicts with pedestrians on east X-walk • Eliminate WB right-turn conflicts with pedestrians on north X-walk • Stop SB thru vehicles from cutting-across west X-walk • Restrict red light running of SB left-turns • Restrict SB vehicles from blocking the intersection • Significantly lessen the number of accidents • Proposed roadway geometric improvements would: • Eliminate the skewed intersection geometry; • Significantly improve pedestrian visibility • Eliminate cut-through traffic on 4th St

  19. Solutions for Safety Issue #1 • Proposed traffic signal phasing improvements would: • Significantly improve the intersection level-of-service; • Eliminate critical SB left-turn and WB right-turn conflicts with pedestrians • Revise traffic signal design to: • Properly align vehicle signal heads with travel lane • Install pedestrian signals on all X-walks • Provide adequate intersection sight distance • Eliminate multiple traffic signals for south leg of Blair Rd • Pedestrian facilities meet new ADA specifications

  20. Safety Issue #2 – Significant Pedestrian-Vehicle ConflictsNorth Crosswalk on Blair Rd Confusing “Pedestrian Use X-walk sign Blair Rd X-walk not visible from WB Cedar St • Businesses located at corner of intersection • also obstruct the sight triangles • WBRT can only observe pedestrians at the • corner of intersection • Confusing “Pedestrian Use X-walk” sign at • corner of intersection should be removed • North X-walk on Blair Road is located far behind the • intersection • Inadequate sight distance for westbound right-turns • (WBRT) to observe pedestrians in north X-walk • Green interval for WBRT coincides with Walk • interval causing direct pedestrian-vehicle conflicts

  21. Safety Issue #2 – Significant Pedestrian-Vehicle ConflictsCrosswalks on Blair Rd and Cedar St SUV making illegal U-turn at opening in raised median Cedar St X-walk not visible from SB Blair Rd SB thru vehicles cut across west X-walk on Cedar St • On-street parking of delivery trucks on WB • Cedar St and NB Blair Rd significantly • obstructs pedestrian visibility • Sight obstructions plus concurrent walk intervals • cause pedestrian-vehicle conflicts on Blair Rd • Median opening allows jaywalking and • illegal U-turn vehicle maneuvers

  22. Solutions for Safety Issue #2 • Relocation of east X-walk on Cedar St and south X-walk on Blair Rd would significantly improve visibility of pedestrians in: • East X-walk on Cedar St for SB left-turns on Blair Rd • North X-walk on Blair Rd for WB right-turns on Cedar St • East and west X-walks on Cedar for NB vehicles on Blair Rd • Split phasing with right-turn overlap operations would: • Eliminate SB left-turn conflicts with pedestrians on east X-walk • Eliminate WB right-turn conflicts with pedestrians on north X-walk • Stop SB thru vehicles from cutting-across west X-walk • Restrict red light running of SB left-turns • Restrict SB vehicles from blocking the intersection • Significantly lessen the number of accidents • Close median opening and install pedestrian channelizing fence on WB Cedar St • Prohibit on-street parking for delivery trucks along Blair Rd and Cedar St

  23. Safety Issue #3 – High Accident FrequencyBlair Rd and Cedar St Approach • SB thru vehicles cut across west X-walk • causing direct pedestrian conflicts • Potential for rear-end accidents with • SBLT on Blair Road • Limited sight distance because of • skewed geometry on Blair Rd • 15 accidents with one pedestrian crash • SBLT frequently run red light at this location • Conflict with vehicles from Cedar St causing • right angle and sideswipe accidents • Conflict with peds in X-walks on Cedar and Blair • due to red light running & limited sight distance

  24. Safety Issue #3 – High Accident Frequency4th St and Cedar St Approach Limited Sight Distance & Confusing Signals on 4th/Blair SB left-turns (SBLT) blocking the intersection • 7 accidents with two pedestrian crashes on this approach • SB left-turns frequently block intersection and run red lights at this location • Conflict with vehicles from 4th St causing right angle and sideswipe accidents • 4th St motorists can’t observe pedestrians on Cedar St due to sight obstructions

  25. Safety Issue #3 – High Accident Frequency4th St and Blair Rd Approach Potential rear-end accident at 4th/Blair Potential right-angle accident at 4th/Blair • 2 right-angle accidents on this approach • Multiple traffic signals confuse motorists • on Blair Rd and 4th St in deciding: • (i) When to leave the intersection and; • (ii) Who has pertinent right-of-way (ROW) • Green interval gives false indication of ROW • causing right-angle and rear end accidents • Inadequate sight distance on 4th St and Blair • Rd causes pedestrian-vehicle conflicts

  26. Solutions for Safety Issue #3 Blair Rd and Cedar St Approach • Relocation of east X-walk on Cedar St and south X-walk on Blair Rd would significantly improve visibility of pedestrians in: • East X-walk on Cedar St for SB left-turns on Blair Rd • North X-walk on Blair Rd for WB right-turns on Cedar St • East and west X-walks on Cedar for NB vehicles on Blair Rd • Split phasing with right-turn overlap operations would: • Eliminate SB left-turn conflicts with pedestrians on east X-walk • Eliminate WB right-turn conflicts with pedestrians on north X-walk • Stop SB thru vehicles from cutting-across west X-walk • Restrict red light running of SB left-turns • Restrict SB vehicles from blocking the intersection • Significantly lessen the number of accidents • Install red light cameras on WB approach of Cedar St and SB approach of Blair Rd • Enforce speed limits by installing speed cameras

  27. Solutions for Safety Issue #3 4th St and Blair Rd Approach • Relocation of south X-walk on Blair Rd would significantly improve visibility of pedestrians for NB vehicles on Blair Rd • Split phasing on Blair Rd in conjunction to “One-way SB Only” maneuver on 4th St would: • Stop SB thru vehicles from cutting-across west X-walk • Restrict red light running of SB left-turns • Restrict SB vehicles from blocking the intersection • Significantly lessen the number of accidents • Revise signal design to eliminate multiple traffic signals • Install red light cameras on SB approach of Blair Rd • Enforce speed limits by installing speed cameras

  28. Solutions for Safety Issue #3 4th St and Cedar St Approach • “One-Way SB Only” maneuver on 4th St would significantly reduce vehicular accidents • Relocation of south X-walk of Blair Rd would significantly improve pedestrian visibility for vehicles on Cedar St • Enforce speed limits by installing speed cameras

  29. Safety Issue #4 – Insufficient Traffic SignageConfusing Traffic Signs • No pedestrian crossing signs on all approaches at this location • No advance warning sign for Blair Rd X-walk on WB approach of Cedar St • Confusing “Right-Lane” and “Pedestrian Use X-Walk” sign on WB Cedar St should be replaced • by appropriate MUTCD traffic signs

  30. Safety Issue #4 – Insufficient Traffic SignageImproperly Placed Traffic Signs • “No Turn On Red” sign is improperly placed on all approaches • Vegetation restricts visibility of traffic signs on EB approach of Cedar St • Damaged sign post on EB approach of Cedar St • Clutter of traffic signage on Blair Rd and Cedar St

  31. Solutions for Safety Issue #4 • Pedestrian crossing signage on all approaches • Advance warning signs for Blair Rd X-walk on WB approach of Cedar St • Replace “Right-Lane” sign with “Stop Here for Pedestrians” (R1-5c, 2009 MUTCD) sign  • Replace “Pedestrian Use X-walk” sign with revised “Side of Street Pedestrian” (R1-6a(1)) sign •  Proper placement of “No Turn on Red Sign” on all approaches • Replace damaged signpost on EB Cedar St • Reorganize traffic signage to eliminate sign clutter • Adequate street lighting in revised signal design

  32. Safety Issue #5 – Faded Pavement MarkingsPotholes & Cracks • Pavement markings are worn or missing adding to motorist confusion • Pedestrian X-walks are in conflict with storm drain facilities • Numerous cracks and potholes in pavements causing safety hazards • Pedestrian facilities are not compliant per the new ADA specifications

  33. Solutions for Safety Issue #5 • Restripe and maintain durable pavement markings at the study intersection • Pedestrian facilities are designed to the new ADA specifications in the revised traffic signal design