A brief review of the history of surface transportation information is given. Interest in intelligent transport systems was revived as a USA policy objective by the 1991 Intelligent Vehicle-Highway Systems Act. Types of intelligent transport systems include advanced traffic management systems, advanced traveller information systems, automated vehicle location (including automatic emergency assistance callout), real time traffic information, and monitoring of speed. The technology used in these systems is discussed. The variable message sign is the most common visual means of disseminating information. Oral information systems including radio traffic broadcasts are described. Cable television, cellular phones and the internet provide new dissemination technologies. Commercial vehicle automated fleet control systems, safety monitoring of commercial vehicles, weigh-in-motion technologies, and interstate traffic information systems are described. Automatic vehicle location is particularly useful to public transport operators, who can use it to ensure their services are appropriately spaced out when traffic congestion disrupts timetables, to inform passengers of when services are due, whether parking is available at public transport terminals etc. Computer based car pooling systems have now been set up. Increasing involvement of the private sector in the financing of such initiatives is anticipated.
Abstract