ABSTRACT
Road accidents constitute an important and emotive issue which no decision maker can afford to be seen to ignore. Improvements in vehicle design, in the delivery of medical care and in traffic engineering have reduced the accident rate (per unit distance driven) and, in some countries, even their absolute number and severity, but road accidents are still a major cause of death and disablement, particularly for young people. In addition to causing human grief and suffering they represent a significant cost to the economy through lost working time, traffic delays, use of emergency services and repairs to vehicles and property. Reduction in the occurrence of accidents through traffic systems design measures can often make a major contribution to the economic benefits of a given project.
