REDUCING COLLISIONS AT HIGH CRASH LOCATIONS

Transcription

1 REDUCING COLLISIONS AT HIGH CRASH LOCATIONS Presented by Nazir Lalani P.E. Traffex Engineers Inc. ACCIDENTS AND SAFETY Why is safety important? Safety components Who is responsible? What is our role? Information resources Examples 1

2 WHY IS SAFETY IMPORTANT? Prevent injury or death Reduce costs to society Provide safe movement Protect all road users Source: Signalized Intersection Information Guide FHWA-HRT

3 SAFETY COMPONENTS Driver Behavior Vehicles Roadway Design RELATIONSHIP OF ELEMENTS Roadway 34% 3 % 27% 57 % Driver 93% 1 % 3 % 6 % 2 % Source: FHWA Vehicle 12% 3

4 DRIVER BEHAVIOR SAFETY TRENDS Vehicle safety devices Increased enforcement Public awareness (DUI, safety belts) Better roadway engineering 4

5 WHO IS RESPONSIBLE? You - The engineering professional Police EMT Politicians Public WHAT IS OUR ROLE? To Enhance Public Safety Develop better engineering designs Collect Traffic data Collect site information Develop collision diagrams Analyze & recommend mitigation measures Implement mitigation measures Measure effectiveness of mitigations 5

6 NATIONAL FATAL COLLISION STATISTICS Total fatalities: 43,443 Road departure: 25,347 Intersection-related: related: 9,188 Pedestrians: 4,881 6

7 Total Crashes Fatalities/Injuries Number % Number % Non-Intersection 3,599, ,022, Signalized Intersection 1,299, , Non-Signalized Intersection 1,418, , Total 6,316, ,967, FHWA guidance on signalized intersections FHWA-HRT Basis of new course on intersection design 7

8 Primary Collision Factors PRIMARY COLLISION FACTORS Speeding (28%) Right-of of-way (18%) Improper turn (10%) Signal or stop sign violations (9%) Under the influence (8%) Pedestrian violation (3%) 8

9 OTHER COLLISION FACTS New drivers (0-19 yrs) % licensed, 10.3 % injury Young drivers (20-29 yrs) % licensed, 25% injury Senior drivers (>65 yrs) - 12% licensed, 6.8% injury PEDESTRIAN STATISTICS On average, a pedestrian is injured in a traffic accident every 8 minutes. On average, a pedestrian is killed in a traffic accident every 111 minutes. In 2005 a total of 4,881 pedestrian were killed in motor vehicle accidents ~ 2,800 were in marked crosswalks In 2005, the per capita pedestrian death rate was 1.6 per 100,000 people 9

10 PEDESTRIANS IN MARKED CROSSWALKS Source: FHWA, Safety Effects of Marked v. Unmarked Crosswalks at Uncontrolled Locations BICYCLE STATISTICS 41.5 percent - bicyclist at fault 51.8 percent - driver at fault 6.7 percent - blamed on both drivers and cyclists, or were inconclusive 10

11 PRIMARY COLLISION FACTORS FOR ONE CITY Rank VC Section Description Count % Caused By % Cited a,c Red Light, Red Arrow % 2.43% Unsafe Speed % 28.6% a Left Turn Yield % 0.17% a Yield from Stop Sign % 0.12% a,b Improper Right/Left Turn % 0.22% a Unsafe Lane Change % 0.63% ,3 DUI 9 4.7% 3.31% a Stop Sign 7 3.6% 5.48% Unsafe Start or Backing 6 3.1% 0.06% Unsafe Movement 4 2.1% 0.19% Total % 41.2% Collision Data 11

12 TRAFFIC COLLISION REPORT Most Useful Information Date/time Location Road user type Pre-collision movements Weather conditions Traffic controls Primary collision factor Officers narrative Witness statements 12

13 Pre-drawn intersections for crash reports A CRASH ANALYSIS STUDY INCLUDES SEVEN KEY STEPS Identify the candidate locations for improvement Identify the main crash trends at a particular location Determine the source of the problems Evaluate improvements to address the crash problems Obtain funding to implement a safety improvement Implement safety improvements Measure effectiveness of implemented improvements 13

14 Identifying Candidate Locations for Improvement COLLISION RATES Collision reports Traffic volumes Normalize stats Three year period of data Segments: collisions per million vehicle miles traveled Intersections: : collisions per million vehicles entering 14

15 COLLISION RATES Segment C x 1,000,000 R = (# Days in Period) x ADT s s x L R = C / MVM C = No. of collisions Period = Yrs x 365days L = Length in miles MVM = Millions of vehicle miles COLLISION RATES Intersection C x 1,000,000 R = (# Days in Period) x ADT s R = C / MVE C = No. of collisions Period = Yrs x 365days MVE = Millions of vehicles entering 15

16 Source: San Luis Obispo, CA, Annual Safety Report

17 Source: New York DOT Source: New York DOT 17

18 Identifying Dominant Crash Patterns COLLISION PROGRAMS & METHODS Intersection Magic/Cross Roads Accident Information Management Software (AIMS): GIS Accident Software Traffic Conflict Method Safety Matrix 18

19 Source: San Luis Obispo, CA, Annual Safety Report 2003 Source: San Luis Obispo, CA, Annual Safety Report

20 Source: San Luis Obispo, CA, Annual Safety Report 2003 Source: Ventura County Annual Safety Report,

21 Source: Ventura County Transportation Department Source: Crash Analysis, Iowa Department of Transportation 21

22 SAFETY MATRIX Pre- Collision Collision Post Collision Vehicle Location Direction of Travel Speed Condition Loading Condition Speed Location Direction of Travel Secondary Impacts Orientation POR Orientation Location of debris Human Impairments Physical Condition Knowledge of area Seating Location Use of restraints Movement of occupants Injuries Direction of ejections Sobriety Evaluation Identification of driver Roadway Weather Road surface Lighting Visibility Traffic controls Changes in conditions since pre- collision Changes in conditions since collision Surrogate Safety Assessment Model 22

23 Final Report FHWA-HRT HRT Final Report FHWA-HRT HRT Surrogate Safety Assessment Model Combines Micro Simulation with Automated Conflict Analysis Frequency and character of narrowly averted vehicular crashes Assess safety of facilities without waiting for statistically above normal number of crashes to occur 23

24 Traffic Conflict Analysis TRAFFIC CONFLICT METHOD BASED ON OBERVATIONS Traffic conflict is a measure of road user risk Traffic conflict occurs when two or more users approach the same point in time and space Measured by the number and severity of near misses Should include vehicle-vehicle and vehicle-other road user conflicts 24

25 Determine Source of the Problem N-S left-turn collisions 25

26 E-W left-turn collisions What indication is on? What is wrong here? 26

27 N-S broadside collisions Severely Restricted Sight Distance 27

28 Evaluate Improvement Needed to Correct the Problem 28

29 RED LIGHT COUNTEREASURES Remove signal sight obstructions Post Signal Ahead warning signs Install/replace signal visors and back plates Add signal back plates Install advance flasher signs Install (additional) 12-inch signal lenses Upgrade signalization Review warrants/consider removing signal Synchronize adjacent signals Red Light Cameras RAN STOP SIGN COUNTEREASURES Remove sign sight obstructions Install larger signs Install Stop / Yield Ahead signs Construct rumble strips in pavement Review warrants/consider removing sign Reverse stop signs if two-way way stop Flashing beacons overhead or on Stop sign Place orange flags on Stop sign 29

30 FAILTURE TO YIELD RIGHT OF WAY AT STOP SIGNS COUNTEREASURES Relocate stop limit line closer to cross street Eliminate parking Remove obstructions from sight triangles Install multi-way stop if warrants are met Install traffic circle if geometrics permit Restrict movements to right-turns turns only IMPROPER TURN COUNTEREASURES Prohibit turns Signalize intersection Revise pavement markings Install raised median Install turn bays Widen approaches to handle turn lanes Improve signing in advance 30

31 Crash Reduction Factors 31

32 TABLES FOR INTERSECTION CRASH REDUCTION FACTORS Table 1: Signalization Countermeasures Table 2: Geometric Countermeasures Table 3: Signs / Markings / Operational Countermeasures Table 1: Signalization Countermeasures for Intersection Crashes Source: Desktop Reference for Crash Reduction Factors Report No. FHWA-SA

33 TABLES FOR ROADWAY DEPARTURE CRASH REDUCTION FACTORS Table 4: Barrier Countermeasures Table 5: Bridge Countermeasures Table 6: Geometric Countermeasures Table 7: Median Countermeasures Table 8: Roadside Countermeasures Table 9: Signs / Markings / Operational Countermeasures Table 6: Geometric Measures for Roadway Departure Crashes Source: Desktop Reference for Crash Reduction Factors Report No. FHWA-SA

34 TABLES FOR PEDESTRIAN CRASH REDUCTION FACTORS Table 10: Signalization Countermeasures Table 11: Geometric Countermeasures Table 12: Signs / Markings / Operational Countermeasures Table 12: Signs / Markings / Operational Countermeasures for Pedestrians Source: Desktop Reference for Crash Reduction Factors Report No. FHWA-SA

35 Obtain Funding To Implement Safety Improvements 35

36 FUNDING ALERNATIVES State funds/grants Federal funds/grants Agency gas tax/sales tax revenues Assessment districts Development agreements Traffic mitigation fees (nexus to development impacts) Conduct Before and After Studies 36

37 Source: ITE Journal, October 1991 INFORMATION RESOURCES USDOT - Federal Highway Administration NHTSA - National Traffic Safety Administration TRB Transportation Research Board ITE

38 Crash Analysis for Directed Enforcement Crashes by time of day 38

39 Sources of Information for Crash Reduction Strategies for Motorized Vehicles REDUCING INTERSECTION COLLISIONS NCHRP REPORT Geometric design Guide for addressing unsignalized intersection Reducing collisions at signalized intersection Highway railroad crossings Red light cameras Road safety audits Roundabouts 39

40 NCHRP Report 500 Volume 12: A Guide for Reducing Collisions at Signalized Intersections NCHRP Report 500 Volume 5: A Guide for Addressing Unsignalized Intersections Collisions 40

41 REDUCING NON-INTERSECTION COLLISIONS NCHRP REPORT 500 Collisions with trees/utility poles Run off the road collisions Head-on collisions Heavy truck collisions Driver distractions Work zone collisions NCHRP Report 500 Volume 7: A Guide for Reducing Collisions on Horizontal Curves 41

42 NCHRP Report 500 Volume 3: A Guide for Reducing Collisions with Trees in Hazardous Locations NCHRP Report 500 Volume 12: A Guide for Reducing Collisions involving Utility Poles 42

43 NCHRP Report 500 Volume 6: A Guide for Addressing Run Off the Road Collisions NCHRP Report 500 Volume 13: A Guide for Reducing Collisions involving Heavy Trucks 43

44 Sources of Information for Crash Reduction Strategies Pedestrians Crossing Roadway An ITE Informational Report by the ITE Pedestrian and Bicycle Council August

45 (Send an to for a pdf) Guidelines Plot, 72 ft (22 m) Pavement, 35 mph (55 km/h), 3.5 ft/s (1.1 m/s) Walking Speed.(8) Pedestrian Volume Crossing Major Road (ped/h) Crosswalk E/A* E/A HC, Red LC* Signal (proposed for MUTCD) 0 No Treatment Major Road Volume - Total of Both Approaches (veh/h) Red *E/A = Enhanced/Active, HC = High Compliance, LC = Low Compliance 45

46 Sources of Information for Crash Reduction Strategies Bicycle Collisions BICYLE CRASH COUNTEREASURES Provide on street striped bike lanes Encourage bicyclists to ride with traffic Colorized treatments to distinguish bike lanes Provide better markings at intersections Providing warning to drivers making turns Remove parking Establish Bike Boulevards Provide better crossings for bike paths 46

47 Warning Sign for Adjacent Bike Path 47

48 Green Bike Turning Lanes (City of SFO) The Netherlands com/ride-a-away Crossing With Overhead Flashers Ventura, CA 48

49 Bike Boulevard Berkeley, CA, USA QUESTIONS? 49