This paper outlines earlier research by the author and his colleagues on the enforcement of speed limits and desirable levels for speed limits. One conclusion was that the most cost-effective way of enforcing speed limits would be to equip vehicles with a manually operated switch on the dashboard, which the driver would set at the current speed limit. When that limit was exceeded, an internal warning would alert the driver and a warning would be displayed outside. A detailed cost-benefit analysis was also conducted to find optimal speed limits. For each class of road in the UK, gains to drivers in terms of reduced journey times and other benefits are balanced against costs to other road users and society in general. Data were used from the Department of Transport speed surveys, value of travel time estimates, and accident costs. The study concluded that UK speed limits should not exceed 55mph on motorways, 50mph on dual-carriageway trunk roads, 40mph on single-carriageway main roads, and 20mph on most urban roads. The corresponding accident rates on such roads would be reduced to 55%, 55%, 80% and 30% of their present levels. Speed control can delivery a wide range of public interest objectives very well; its potential as an immenseley powerful tool of transport policy is not yet realised and needs more publicity. For the covering abstract see IRRD E100685.


  • English

Media Info

  • Features: References;
  • Pagination: 4 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00764382
  • Record Type: Publication
  • Source Agency: Transport Research Laboratory
  • Files: ITRD
  • Created Date: May 28 1999 12:00AM