This report examines some aspects of speed limits and their enforcement. Speed measurement techniques by radar and amphometer, speed survey results and the application of speed limits are discussed. The major points to emerge are that whilst speed measurement devices can be accurate, they have their limitation. The speed survey data examined show that the majority of vehicle free speeds were above the speed limit in urban areas, but usually below the speed limit in rural areas. In-depth crash studies in Sydney have shown that many vehicle pre-crash speeds were excessive even though they were below the speed limit. In such cases speed limits do not seem to have the desired effect on vehicle free speeds and crashed. A reappraisal of the present system of speed limits is suggested. (A)
Abstract