An experimental evaluation of in-vehicle collision avoidance systems

This report describes a simulator study in which seven candidate in- vehicle CAS (collision avoidance systems) were compared as to their effects on driving behavior in car-following situations. The use of the CAS systems studied is accompanied by behavioral changes affecting the way in which the driving task is performed. In general, the following effects seem to be associated with the availability of a CAS: 1) a change in the distribution of time headways, in particular a reduction in the occurrence of very short headways, 2) an increase in driving speed, 3) an increase in acceleration and deceleration levels and 4) an increase in time spend driving in the left land of the road.