In this report, a description is given of a number of practical experiments that are being carried out with Intelligent Speed Adaptation (ISA) in Sweden and the Netherlands at the present time. In Sweden, the ISA experiment is being carried out in four cities with various types of 'warning when driving too fast' involving about 8,000 vehicles. In the Dutch experiment, in the city of Tilburg, the ISA system intervenes as soon as the speed limit is going to be excelled. This is done by 'cutting off' the supply of fuel. Twenty vehicles are involved during a one year period. Other ISA research that has been carried out involved, among other things, a simulation in England. An important question arising from large-scale ISA introduction in the Netherlands, is its possible effects on road safety. The report presents a number of approximate estimations of the effects to be expected. These effects have an estimated reduction in accident victims from 25 to 30%. The estimations do not take into account, for example, gradual introduction, changing driving behaviour, and possible system failure. Although ISA appears to have a large safety-improving potency, it is recommended to wait for larger-scale practical experiments. This applies especially to roads with 50 km/h and 80 km/h speed limits. Only such studies can provide a definite answer to the real size of the expected effects.
Abstract