This particular literature study addresses a number of the issues surrounding a lowering of speed limits in urban areas; a relatively low-cost measure that is likely to have a positive impact on safety but also a negative impact of some magnitude on mobility. The relationship between vehicle speed and accident outcome severity is well established. Research also indicates that even modest speed reductions can prevent the occurrence of collisions and significantly reduce the outcomes of those crashes that do occur; particularly those that involve vulnerable road-users who are more predominant in the urban environment. In addition to safety, there are other potential benefits to be gained by speed limit reductions in urban areas. Those suggested in the literature include an increase in traffic flow and consequent reduction in congestion and delays, particularly where the roads are functioning at near capacity. Further, reductions in speed bring about a reduction in vehicle operating costs with less wear and greater energy (fuel) efficiency, and less pollution and noise. (a) For the covering entry of this conference, please see ITRD abstract no. E216178.
Abstract