RESEARCH - The Impact of Lowering Speed Limits in Urban Areas
The majority of all traffic collisions occur in the urban environment, where there is a more complex traffic environment and a higher predominance of road users that are more susceptible to injury and fatality in the event of an accident. A relatively straightforward and cost-effective speed management measure, involves reducing speed limits.
The relationship between vehicle speed, accident risk and accident outcome severity is well established in traffic safety literature. Research shows that reduced speed is likely to bring about a reduction in average travel speed and have a positive impact on both the number of accidents and accident outcome severity.
Other secondary benefits are also derived including: reduced fuel and vehicle operating costs, and significant reductions in vehicle emissions and noise.
The document The impact of lowered speed limits in urban and metropolitan areas is from 2008, but appropriate speed limit setting is part of Vision Zero today. This reference from the ITE, Speed Management for Safety is a guide for traffic engineers and may be of interest to the public.