ROAD SPEED LIMITS

Issues to be considered in setting road speed limits include: safety, fuel consumption, noise, air pollution, and accommodation of pedestrians and cyclists. A distinction is made between an official speed limit, as indicated by roadside signs, and the corresponding real speed limit, the minimum speed at which the police would act. Traffic calming in effect provides self-enforcing speed limits, although this can bring problems. It is applied to suburban roads, estate roads within the grounds of institutions, and main roads in urban and rural areas, scenic areas, and urban centres. Criteria for choosing its measures include: effectiveness in limiting speed, costs of setting up and operation, public acceptability, possible exemptions for important vehicle classes, damage to vehicles and harm to their occupants, noise creation, and safety. Its objectives include pedestrian safety and convenience, environmental improvement, and reduced access for vehicles. Transport telematics has many potential applications to traffic control and management, and provides a flexible way of implementing road speed limits. Some widely differing views on speed limits are summarised. Decisions will be needed in the future about what speed limits there should be, at what speeds, and how they should be enforced. For the covering abstract see IRRD E100674.