Synthesis of Safety for Traffic Operations - Transports Canada

Synthesis of Safety for Traffic Operations March 2003
Unsignalized Intersections
Three Approaches:
N = 0.00250 TOTAL 0.614 RATIO 0.5253
N = 0.00732 TOTAL 0.614 RATIO 0.5253
Casualty crashes
PDO crashes
Four Approaches:
N = 0.00072 TOTAL 0.838 RATIO 0.591
N = 0.00164 TOTAL 0.838 RATIO 0.591
Casualty crashes
PDO crashes
where:
TOTAL = AADT main + AADT minor
RATIO = AADT minor / TOTAL
AADT main = Average daily traffic entering from the main road
AADT minor =Average daily traffic entering from the minor road
Pernia et al (2002)
Florida
Unsignalized Intersections
N = exp(0.6827 + 0.2777ADT + 0.1193LU + 0.1705L – 0.1695SL + 0.2752M – 0.1679S)
where:
N = Annual number of crashes
ADT = 0 if ADT < 15,000; 2 if ADT > 30,000; 1 otherwise
LU = 1 if urban; 0 otherwise
L = 1 if > 4 lanes on major road; 0 otherwise
SL = 1 if posted speed limit on major road > 45 mph; 0 otherwise
M = 1 if median on the major road; 0 otherwise
S = 1 if paved shoulders; 0 otherwise
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