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?