Driver Speed Compliance in Western Australia
A state-wide speed survey was conducted over the period March to June 2000 to measure driver speed compliance and to collect baseline data for future annual surveys which will be used to measure changes in driver speed behaviours on the road network.
A stratified random sample was chosen which consisted of 194 sites across the state road network, covering Perth metropolitan and rural regions, National and State Roads, as well as Local Roads. Sample sizes by the strata were based on regional and road type vehicle-kilometres-travelled estimates. Traffic volume, speed and vehicle composition data was collected using vehicle classifiers.
The results of the survey indicated that over 45% of WA drivers in a ?free? flowing traffic environment exceed speed limit and 12% exceed the enforcement speed limit. Speed compliance varies by speed limit between the metropolitan and rural areas, as well as between rural regions. Metropolitan drivers are more likely to exceed speed limits during the night hours while rural drivers tend to drive at higher speeds during daylight hours. Heavy vehicle drivers in the metropolitan area tend to exceed the speed limit more frequently than lighter vehicle drivers. Drivers in rural areas are twice as more likely to speed on 60 km/h local roads than metropolitan drivers. Over the total road network, driver speed compliance is less on week-ends than on working days of the week. Average non-compliance rate to the enforcement speed limit is not significantly different between metropolitan and rural drivers, being approximately 12%.