Is it reliable that speed-calming solutions as ISA can reach the drivers, who needed it most?

A significant number of trials with Intelligent Speed Adaptation (ISA) have been carried out within the last two decades. Almost all with a promising result; the drivers reduce their proportion of speeding and are in general positive to ISA. However, two tings question this offhand success story; 1: there has been no commercial break through for ISA so far, even though estimated has shown that ISA can reduce the n. of fatalities in traffic accidents with up to 59%, and 2: in the only ISA trial included drivers, who not participated voluntary in the trial, ISA had virtually no effect on these drivers. The ISA trial with involuntary participants was known as ISA C and was carried out in and around the Danish town Vejle 2007-2008. First an ultra short presentation to ISA will be given. It will be followed by a project presentation of ISA C followed with the most significant results regarding the involuntary drivers and other circumstances, which can have resulted in the limited effect from ISA in the trial. Finally, there will be presented some considerations about ISA and involuntary drivers in general – are there national differences and has the attitude changed in the last year to a more safety-oriented view in the public?