Contributing Crash Factors, Countermeasure Selection, and Evaluation

Module 4-1

Tracking your way through Road Safety 101

Core Competency 4:

Module 1: Contributing Crash Factors and Interactions

Module 2: Scientific Principles for Effective Road Safety Analysis

Module 3: Problem Identification

Module 4: Countermeasure Selection

Module 5: Cost Effectiveness of Alternative Countermeasures

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Crash Contributing Factors & Interactions

Identify contributing crash factors and how they interact.

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Major Topics

Human Crash Factors

Roadway Crash Factors

Vehicle Crash Factors

Environmental Crash Factors

Analysis Methods

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Human Crash Factors

Demographic Factors

• Age

• Gender

• Racial and Ethnic Groups

Behavioral Factors

• Aggressive driving

• Impaired driving

• Occupant protection

• Illegal Driving

• Driver Inattention

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Roadway Crash Factors

Exposure

Facility type

• Interstates and freeways

• Rural roads

• Intersections

• Pedestrian facilities

• Bicycle facilities

Non Intersection1749 (10.7%)

$12.7M (13.7%)

Non-Interchange994(6.1%)

$7.83M (8.4%)

Interchange 119 (0.7%)

$0 (0.0%)

Intersection450(2.7%)

$4.53M (4.9%)

Intersection640 (3.9%)

$0 (0.0%)

Non Intersection1583 (9.7%)

$0 (0.0%)

Intersection964 (5.9%)

$1.87M (2.0%)

Non Intersection 553 (3.4%)

$22.8M (24.5%)

SVROR = 461 (2.8%)Shoulder/Rumble = $7.34M (7.9%)

SVROR = 685 (4.2%)Shoulder/Rumble = $11.5M (12.4%)

Right Angle = 188 (1.1%)Rear End = 19 (0.1%)

SVROR = 15 (0.1%)Other = 18 (0.1%)

Signal = $0.007M (0.0%)Turn Lanes = $1.96M (2.1%)

Signal & Turn Lanes = $2.52M (2.7%)Other = $0.105M (.1%)

Right Angle = 572 (3.5%)Rear End = 62 (0.4%)SVROR = 196 (1.2%)

Signal = $0.364M (0.4%)Turn Lanes = $0.606M (0.6%)

Other = $0.896M (0.1%)

Right Angle = 248 (1.5%)Rear End = 55 (0.3%)

SVROR = 66 (0.4%)Other = 81 (0.5%)

Signal = $0.496M (0.5%)Turn Lanes = $3.53M (3.8%)

Other = $0.500M (0.5%)

Rear End = 181 (1.1%)Other = $0.487M (0.5%)

Cross Median = 125 (0.8%)Centerline/Median = $0 (0.0%)

SVROR = 253 (1.5%)Shoulder/Rumble = $22.1M (23.8%)

Rear End = 98 (0.6%)Other = 156 (1.0%)

Other = $0.487M (0.5%)

Cross Median/Head On = 46 (0.3%)Centerline/Median = $0.122M (0.1%)

C L/Head On = 608 (3.7%)Centerline/Median = $1.3M (1.3%)

Rear End = 139 (0.8%)Other = 317 (1.9%)

Other = $0 (0.0%)

Unpaved = 2223 (13.6%)$ 0 (0.0%)

Paved = 3773 (23.0%)$7.97M (8.5%)

Freeway = 1113 (6.8%)$7.83M (8.4%)

Two-Lane = 2199 (13.4%)$17.2M (18.5%)

Expressway = 793 (4.8%)$27.4M (29.5%)

SVROR = 1637 (10.0%)Shoulder/Rumble = $4.86M (5.2%)

Rear End = 150 (0.9%)Right Angle = 167 (1.0%)

Other = $1.24M (1.3%)

Head On = 237 (1.4%)Centerline/Median = $0 (0.0%)

Non Intersection2809 (17.1%)$6.1M (6.6%)

Rural = 10101 (62.0%)$60M (65.0%)

State System = 4105 (25%)$52M (56%)

Local System = 5996 (36.5%)$7.97M (8.5%)

Urban = 6182 (38.0%) $33M (35.0%)

Statewide16388 $93M

Intersection240(1.5%)

$4.6M (4.9%)

Rural Disaggregation by Facility Type 2001-2008 K+A Crashes, Safety Funding 2001-2011 (HSIP+TSIP)

Not Colored in Analysis

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Facility Types

Divided Highways

• Interstates/Freeways

• Expressways

Undivided Highways

• Multi-lane

• 2 lane

Rural/Urban roads

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Facility Types (cont.)

Intersections

Source: NCHRP Report 500: Vol. 12, Signalized Intersections, NAS, 2004)

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Facility Types (cont.)

Pedestrian Facilities

Bicycle Facilities

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Vehicle Crash Factors

Crash Avoidance

Crash Survivability

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Crash Avoidance

Suspension

Braking

Vehicle Mass

Low Center of Mass

Driver Aids

Traction

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Crash Survivability

Safety Equipment

Propensity for Rollover

Energy Absorption

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Environmental Crash Factors

Rain

Snow, Sleet, & Ice

Fog

Wind and sun

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Methods for Studying Crash Factors

Crash Factor Interactions

Observational Studies

• Crash investigation and reconstruction

• Observational data

• In-vehicle monitoring

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Crash Data Analysis

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Crash Investigation & Reconstruction

http://www.youtube.com/

watch?v=VheS0CpmE-k

http://www.youtube.com/

watch?v=4DRWGy5Ba3w

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Simulator Experiments

Source: www.cgsd.com/DrivingSimulator/ds100.html

http://www.youtube.c

om/watch?v=TJpTp7djeN

U

http://www.cgsd.

com/DrivingSim

ulator/DS230.avi

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In-Vehicle Monitoring

http://espanol.video.yahoo.com/watch/5018797/13350370

http://www.idrive.pro/us/index.php

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Review

Human Crash Factors

Roadway Crash Factors

Vehicle Crash Factors

Environmental Crash Factors

Analysis Methods

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Exercise #5 Crash Factors

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