Almost all drivers sometimes exceed the speed limit, and many exceed it at almost every opportunity. Experience shows that much the most effective way of reducing speeds is to make it difficult or impossible to drive faster than the maximum speed that the highway authority wishes to set. Traffic calming is effective but expensive, but has several disadvantages; for example, it cannot be used on motorways and other fast roads. This paper considers the possibility of using intelligent speed adaptation (ISA), also known as external vehicle speed control (EVSC), through various forms of intelligent vehicle speed limiter. These systems require: (1) some communication between vehicle and road, so that the vehicle knows the current speed limit; (2) an on-board control unit to compare allowed speed with actual speed; and (3) links to the vehicle's power train and brakes. Advanced technology now allows the reliable operation of such equipment, using a combination of a global positioning system (GPS), a digital road map, and adaptive cruise control (ACC). The paper discusses the predicted safety benefits of the UK's EVSC project, its experimental design, its results with traffic light violations, car following, and motorway driving in fog, and whether driver attitudes will change as a result of using ISA.
Abstract