Synthesis of Safety for Traffic Operations - Transports Canada

Legislation and Enforcement
non-intersection and parking crash rates, and the proportion of parking crashes as the
metrics. Parking crashes were defined as crashes that involved a parked vehicle or a
vehicle that was either parking or unparking. Crashes that were caused by a vehicle
slowing or stopped to park, but that did not involve the parking vehicle were not included
in parking crashes because of limitations on data.
The crash rates for the different types of parking are shown in Table 8.15.
TABLE 8.15: Crash Rates for Curbside Parking in Nebraska
Type of Parking Major Street
Two-way, two-lane streets
Nonintersectiointersection
Non-
Parking
Parking
Crash Rate
Crash Rate
Crash Rate
Crash Rate
Crashes per MVM
Painted Parking
Parallel 1.65 0.55 1.83 0.85
Low-angle --- --- 3.38 2.60 +
High-angle 1.20 0.53 3.59 2.91 +
Unpainted
Parking
Parallel 1.32 0.28 0.67 0.26
Angle 1.57 0.52 1.67 1.11 +
Crashes per BVMHPS*
Painted Parking
Parallel 6.50 2.17 6.58 3.05
Low-angle --- --- 9.59 7.38 +
High-angle 7.19 3.19 12.90 + 10.50 +
Unpainted
Parking
Parallel 7.67 1.65 5.44 2.13
Angle 13.19 + 4.40 + 12.10 + 8.04 +
*BVMHPS = Billion vehicle-miles-hours per stall
+ Significantly different from equivalent parallel parking at 5% level of significance
The crash rates calculated using exposure that is based on traffic volume and parking
activity (i.e., crashes per BVMHPS) is likely to provide the most valid measure of the
relative safety of the different types of curbside parking. In all cases, the streets that
permit parallel parking have lower crash rates than the streets with angle parking.
Moreover, the low-angle parking yields typically lower crash rates than the high-angle
parking streets.
Recognizing the limitations of a cross-sectional study in determining the relative safety of
a particular treatment, McCoy et al attempted to control for several confounders by re-
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