Rating Infrastructure for Pedestrian Safety
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Transforming Transportation Transforming Transportation Pedestrian Safety and Public Transport for Pedestrian Safety and Public Transport for Vulnerable Populations, Januray 15, 2009 Vulnerable Populations, Januray 15, 2009 Infrastructure Safety Rating for Pedestrians Said Dahdah Road Safety Specialist
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By Dr. Said Dahdah, World Bank (Washington, D.C., USA)
Transcript of Rating Infrastructure for Pedestrian Safety
Transforming TransportationTransforming TransportationPedestrian Safety and Public Transport for Vulnerable Pedestrian Safety and Public Transport for Vulnerable Populations, Januray 15, 2009Populations, Januray 15, 2009
Infrastructure Safety Rating for Pedestrians
Said Dahdah
Road Safety Specialist
System user
Problem of crashes
System designer
Problem of injury
FROM FOCUS ON CRASHESTO FOCUS ON INJURIES
Swedish Road Administration
Swedish Road Administration
Vision Zero philosophyIntegration and Separation.
1. Vulnerable road users should not be exposed to motorised vehicles at speeds exceeding 30 km/h
2. If 1. cannot be satisfied then separate or reduce vehicle speed to 30 km/h
Why 30 km/h?
0.0%
20.0%
40.0%
60.0%
80.0%
100.0%
0 10 20 30 40 50 60 70 80
Impact Speed (km/h)
Ris
k of
Ped
estr
ian
Fat
al I
njur
y
Car
LTV
Risk Concept
Risk Model for Pedestrian Crashes
Along
Crossing
Pedestrian
Likelihood
Protection
Area Factor
Likelihood
Protection
Area Factor
Likelihood of Pedestrian Crashes
• Likelihood Factor for “walking along” the road crashes =
Speed factor x Sidewalk provision factor x Side friction factor
Likelihood of Pedestrian Crashes
Likelihood of Pedestrian Crashes
• Likelihood Factor for “crossing” the road crashes =
Speed factor
x Number of lanes for use by through traffic factor
x Median type factor
x Pedestrian crossing facilities factor
x Quality of crossing factor
Likelihood of Pedestrian Crashes
Likelihood of Pedestrian Crashes
• “Walking Along” Crash Likelihood Factor =0.7• “Crossing” Crash Likelihood Factor = 3.6• Ideal Road LF (both crash type) = 0.25
Risk Concept
Severity of Pedestrian Crashes
• Severity Factor for Pedestrian Crashes =
Speed factor
X Age factor
X Vehicle type factor
Severity of Pedestrian Crashes
Safety Rating for Pedestrians
• Road Prevention and Protection Score (RPPS) =
Likelihood factor * Protection factor (Risk)
Safety Rating
Fatality Prediction Model
• Fatality/km = RPPS*Country Factor
*Exposure Factor*Traffic Flow
Country Factor = (Fatality/100 million veh-km)/RPPS
Exposure Factor = Pedestrian Flow Effect
(exponent 0.4)
Country Factor (China)
y = 1.9459x
R2 = 0.4691
0123456789
0 1 2 3 4 5RPPS
Fata
lity
rate
per
100
m
illio
n ve
h-km
China Country Factor = 2 (RPPS 1 2 Fatalities per 100 million veh-km)
Economic Analysis of Transport Projects
• Travel Time Saving
• Vehicle Operation Cost
• Why not Safety?
