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
Module 4-1
Crash Contributing Factors & Interactions
Identify contributing crash factors and how they interact.
Module 4-1
Major Topics
Human Crash Factors
Roadway Crash Factors
Vehicle Crash Factors
Environmental Crash Factors
Analysis Methods
Module 4-1
Human Crash Factors
Demographic Factors
• Age
• Gender
• Racial and Ethnic Groups
Behavioral Factors
• Aggressive driving
• Impaired driving
• Occupant protection
• Illegal Driving
• Driver Inattention
Module 4-1
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
Module 4-1
Facility Types
Divided Highways
• Interstates/Freeways
• Expressways
Undivided Highways
• Multi-lane
• 2 lane
Rural/Urban roads
Module 4-1
Facility Types (cont.)
Intersections
Source: NCHRP Report 500: Vol. 12, Signalized Intersections, NAS, 2004)
Module 4-1
Facility Types (cont.)
Pedestrian Facilities
Bicycle Facilities
Module 4-1
Vehicle Crash Factors
Crash Avoidance
Crash Survivability
Module 4-1
Crash Avoidance
Suspension
Braking
Vehicle Mass
Low Center of Mass
Driver Aids
Traction
Module 4-1
Crash Survivability
Safety Equipment
Propensity for Rollover
Energy Absorption
Module 4-1
Environmental Crash Factors
Rain
Snow, Sleet, & Ice
Fog
Wind and sun
Module 4-1
Methods for Studying Crash Factors
Crash Factor Interactions
Observational Studies
• Crash investigation and reconstruction
• Observational data
• In-vehicle monitoring
Module 4-1
Crash Data Analysis
Module 4-1
Crash Investigation & Reconstruction
http://www.youtube.com/
watch?v=VheS0CpmE-k
http://www.youtube.com/
watch?v=4DRWGy5Ba3w
Module 4-1
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
Module 4-1
In-Vehicle Monitoring
http://espanol.video.yahoo.com/watch/5018797/13350370
http://www.idrive.pro/us/index.php
Module 4-1
Review
Human Crash Factors
Roadway Crash Factors
Vehicle Crash Factors
Environmental Crash Factors
Analysis Methods
Module 4-1
Exercise #5 Crash Factors
21