Freeway Speed Zones: Safety and Compliance Issues

The effectiveness and appropriateness of establishing speed limits on freeways and the spatial extent of the zones were studied. Of particular interest were 55-mph (88-km/hr) speed zones that exist in the transition between urban and rural areas (determined according to urban area boundaries). Three types of freeway segments (urban-55, fringe-55, and rural-65) were analyzed, and although the study was of comparatively small scale, the results generally showed that higher speeds do not lead to more numerous or serious accidents. Moreover, compliance with speed limits is not necessarily a good measure of safety. On the other hand, motorists are self-policing to a certain degree in that they drive at reasonable speeds given the design of the different types of freeways. It is suggested that artificially lowered speed limits without a clear need being established from engineering and safety perspectives will not yield impressive safety benefits.