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Webinar Resource Documents

Webinar Resource Documents. Have you downloaded for Today’s Webinar? (-using the file share pod). PowerPoint Handout for Today’s Webinar FHWA Signalized Intersections Countermeasures Issue Briefs Sheet #8 Toolbox of Countermeasures – Crash Reduction Factors

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Webinar Resource Documents

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  1. Intersection Safety Webinar

  2. Webinar Resource Documents • Have you downloaded for Today’s Webinar? (-using the file share pod) • PowerPoint Handout for Today’s Webinar • FHWA Signalized Intersections Countermeasures • Issue Briefs Sheet #8 Toolbox of Countermeasures – Crash Reduction Factors • Dynamic Dilemma Control System for high speed isolated rural signals Intersection Safety Webinar

  3. Before the webinar starts or after, to download information/files, in the “Download these Files” file share pod, highlight each file and “Save to Your Computer” Intersection Safety Webinar

  4. to download, click on “pods”, then click on “File Share Pod” to open, then highlight each file you wish to download, then click on “Save to My Computer” Intersection Safety Webinar

  5. Agenda – Improving Safety for Signalized Intersections • Overview of Signalized Intersection Safety • Identify Proven Countermeasures to Improve Safety of Signalized Intersections • Review Application of Countermeasures to Signalized Intersections Intersection Safety Webinar

  6. U.S. National Total Crash Characteristics 53% 55% Intersection Safety Webinar

  7. U.S. YEARLY Average Number of FATAL + INJURY Crashes by TRAFFIC CONTROL (2002 - 2006) Intersection Safety Webinar

  8. Signalized Intersection Proven Countermeasures NCHRP 500 – Volume 12: A Guide for Reducing Collisions at Signalized Intersections FHWA Signalized Intersections: an Informational Guide FHWA Briefing Sheet #8 – Crash Reduction Factors for Intersections Intersection Safety Webinar

  9. Signalized Intersection Safety Strategies • Signalized Intersection Safety Strategies • Individual Strategy Sheets for each of the 28 Signalized Intersection Strategies • from NCHRP 500 – Volume 12: A Guide for Reducing Collisions at Signalized Intersections Intersection Safety Webinar

  10. The Two Overall Principles for Signalized Intersections: • Clarify • Simplify Intersection Safety Webinar

  11. Improving Safety for Signalized Intersections • Provide info in advance of where it is needed (warning + navigation) • “Spread” decisions • Keep workload at “medium” level • Maximize visibility of signal Indications/stop signs + beacons Apply “Clarify” and “Simplify”: Intersection Safety Webinar

  12. Applying Clarify and Simplify Warning • Signal Control of 2 rural State Highways Intersection Safety Webinar

  13. Applying Clarify and Simplify Guide • Signal Control of 2 rural State Highways Intersection Safety Webinar

  14. Applying Clarify and Simplify Guide • Signal Control of 2 rural State Highways Intersection Safety Webinar

  15. Applying Clarify and Simplify Lane Use Signing - Overhead • Signal Control of 2 rural State Highways Intersection Safety Webinar

  16. Applying Clarify and Simplify Markings • Signal Control of 2 rural State Highways Intersection Safety Webinar

  17. Applying Clarify and Simplify Signal Head per Lane Supplemental Far Side Signal Head • Signal Control of 2 rural State Highways Intersection Safety Webinar

  18. Applying Clarify and Simplify Backplates Intersection Safety Webinar

  19. Applying Clarify and Simplify ITE Clearance Intervals Intersection Safety Webinar

  20. Applying Clarify and Simplify Questions and Discussion Intersection Safety Webinar

  21. Is this Intersection as ‘safe’ as it could be? • What are some Traffic Signal Features/Equipment that affect Safety? • Let’s discuss Discussion Intersection Safety Webinar

  22. Traffic Signal Countermeasures: 1. Update yellow Clearance timing 2. Add All-Red Clearance phase 3. Advance Detection for Rural Signals 4. Improve visibility (12” sections, suppl. heads, etc) 5. Add Back Plates • Change Permissive Lefts to Protected Only • Change Leading Protected Left to Lagging Protected Left Intersection Safety Webinar

  23. Traffic Signal Countermeasures: 8. Add Advance Warning signs with active flashers 9. Add Supplemental Signal Heads 10. Use Overhead Red “T” Heads 11. Change Late Night Yellow/Red Flash to Full Time Signal 12. Countdown Pedestrian Indications 13.Coordination of Signals • Signal Spacing • Lighting Intersection Safety Webinar

  24. Engineering Countermeasures to Red-Light Running: *TTI, Bonneson, 2003 Intersection Safety Webinar

  25. Signalized Intersection Countermeasures: ITE Traffic Engineering Handbook 1. Update Yellow Clearance Interval Yellow Time All-Red Time NY study: 9% decrease in multi-vehicle crashes NY study: CRF =8% total crashes CRF = 12% injury crashes CRF = 39% ped crashes *NCHRP 500, Objective 17.2 A2 – Optimize Clearance Intervals Intersection Safety Webinar

  26. Signalized Intersection Countermeasures: 1. Update Yellow Clearance Interval CRF = 15% total crashes CRF = 30% right angle crashes *TTI, Bonneson, 2003 *NCHRP 500, Objective 17.2 A2 – Optimize Clearance Intervals Intersection Safety Webinar

  27. Signalized Intersection Countermeasures: 1. Update Yellow Clearance Interval • reduces RLR frequency by 50-70% *TTI, Bonneson, 2003 AMF = 0.92 Total Crashes AMF = 0.96 Right Angle Crashes AMF = 0.63 Ped/Cyclist Crashes Intersection Safety Webinar

  28. Signalized Intersection Countermeasures: 2. Add All-Red Clearance Interval ITE Traffic Engineering Handbook – All-Red Clearance Interval CP = ( W + L) / V Example: 85th speed=45mph, W=36, curb radius=50’, L=20’ = (W+L)/V = (50 + 36 + 20)/45*88/60 = 106/66 = 1.61seconds All-Red Time Intersection Safety Webinar

  29. Signalized Intersection Countermeasures: ACS-Lite http://www.ops.fhwa.dot.gov/acs_lite/ http:// www.ops.fhwa.dot.gov/ arterial_mgmt/pubs.htm Intersection Safety Webinar

  30. Signalized Intersection Countermeasures: Traffic Signal Timing Manual Summer 2008 http:// www.ops.fhwa.dot.gov/ arterial_mgmt/pubs.htm Intersection Safety Webinar

  31. Signalized Intersection Countermeasures: Advanced Dilemma Zone Detection for Rural High Speed Approaches 3. Advance Detection CRF = 39% Injury Crashes Intersection Safety Webinar

  32. Advanced Dilemma Zone Detection for Rural High Speed Approaches: *Bonneson, TTI, 2005 Intersection Safety Webinar

  33. Advanced Dilemma Zone Detection for Rural High Speed Approaches: *Bonneson, TTI, 2005 Intersection Safety Webinar

  34. Advanced Dilemma Zone Detection for Rural High Speed Approaches: Intersection Safety Webinar

  35. Dynamic Dilemma Zone Detection Questions and Discussion Intersection Safety Webinar

  36. Signalized Intersection Countermeasures: 4. Improve Visibility (12” Indications, Supplemental heads) Increasing indications from 8” to 12” CRF = 11% total crashes CRF = 46% right angle crashes *NCHRP 500, Strategy 17.2 D2: Improve Visibility of Signals CRF = 49%for change from pedestal position to mast arm position Intersection Safety Webinar

  37. Signalized Intersection Countermeasures: 4. Improve Visibility (LED Indications) CRF = 17% total crashes CRF = 10% right angle crashes CRF = 10% rear end crashes *NCHRP 500, Strategy 17.2 D2: Improve Visibility of Signals Intersection Safety Webinar

  38. Signalized Intersection Countermeasures: 4. Improve Visibility (Additional Primary Head) CRF = 28% total crashes CRF = 35% right angle crashes CRF = 28% rear end crashes *NCHRP 500, Strategy 17.2 D2: Improve Visibility of Signals Intersection Safety Webinar

  39. Signalized Intersection Countermeasures: 4. Improve Visibility (Signal Head per Lane) 1 head for 1 Lt lane 4 heads for 4 lanes 1 head for 1 Rt lane CRF = 7% total crashes CRF = 46% right angle crashes *NCHRP 500, Strategy 17.2 D2: Improve Visibility of Signals Intersection Safety Webinar

  40. Signalized Intersection Countermeasures: 4. Improve Visibility (Supplemental Signal Heads) Supplemental Signal Head 48% Reduction in Right Angle Crashes Winston-Salem, NC Intersection Safety Webinar

  41. Signalized Intersection Countermeasures: 5. Add Back Plates CRF = 13% total crashes CRF = 50% right angle crashes Back Plates No Back Plates Intersection Safety Webinar

  42. Signalized Intersection Countermeasures: 5. Add Back Plates -50% reduction in RLR * Bonneson Intersection Safety Webinar

  43. Signalized Intersection Countermeasures: Retro- reflectorized backplate 5. Add Back Plates Intersection Safety Webinar

  44. Signalized Intersection Countermeasures: 5. Add Retro-Reflectorized Back Plates CRF = 15% Intersection Safety Webinar

  45. Visibility of Signal Indications Questions and Discussion Intersection Safety Webinar

  46. Signalized Intersection Countermeasures: Add a Left Turn Lane + Protected Left Turn Phase CRF = 58% total crashes) *NCHRP 500, Strategy 17.2 A1 – Employ Multiphase Signal Operation Intersection Safety Webinar

  47. Signalized Intersection Countermeasures: 6. Change Protected Left Only to Protected/Permissive *NCHRP 500, Objective 17.2 A1 – Provide Protected Left Turn Signal Phase CRF= 4% total crashes CRF = -65% left turn crashes CRF = -10% injury crashes Intersection Safety Webinar

  48. Signalized Intersection Countermeasures: 7. Change Leading Protected Left to Lagging Left Protected CRF= - 15% total crashes CRF = - 49% Left Turning Crashes Intersection Safety Webinar

  49. Treatment Finding Post SIGNAL AHEAD warning signs—urban(98) 16%-35% estimated decrease in all collisions. Post SIGNAL AHEAD warning signs—rural(98) 16%-40% estimated decrease in all collisions. Post SIGNAL AHEAD signs(135) 44% estimated decrease in right-angle collisions. Advance-warning flasher (172) 44% decrease in all fatal/injury 53% decrease in pd crashes 73% decrease in all fat/inj-angle crashes. 82% decrease in all rear-end fatal-injury Signalized Intersection Countermeasures: 8. Add Signal Ahead Advance Warning Sign Intersection Safety Webinar

  50. Signalized Intersection Countermeasures: Flashers for Intersection Warning Signs Be Prepared to Stop with Activated Flasher Intersection Safety Webinar

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