In Great Britain during 1983, some 58 per cent of goods movement and 92 per cent of all passenger traffic took place by road, where delays due to major incidents cost about £100 m per year. A further cost of about £800 m could also be prevented if drivers were able to find the least cost route on all unfamiliar parts of the road network. Motorists have expressed a need for information on the weather and the state of the roads, the general traffic situation and any abnormal congestion. Road signs are the most important source of information, several experimental automatic warning signs installed in germany and holland have significantly reduced accidents. Radio broadcasts are used to transmit information at national and local level, either superimposed on normal transmissions or on a dedicated channel. Recent advances in microcomputers and data storage techniques have resulted in the production of self-contained navigational and route guidance aids. In-car systems to compute route directions should produce higher savings to drivers than those giving only network displays and positions. Externally linked in-car systems will have cheaper in-vehicle equipment. Data received by the in-car unit are normally concerned with location parameters enabling the position to be determined and updates of road traffic conditions are used for route guidance. For the covering abstract of the conference see IRRD 294062.
Abstract