Samenvatting
A method of evaluating an automatic queue warning system is outlined. The main object of the evaluation is to measure the effect of such a system on traffic behaviour and road safety, although the overall journey time is also examined. The chosen method of research entails before and after studies, if possible complemented with control groups. Factors likely to have a disturbing effect on this method of research are also discussed, together with their respective solutions. Finally, a look is taken at the number of accidents required for a statistically reliable analysis.