Prototypes of integrated behavioural assessment systems have been tested in driving simulators and in actual vehicles. On-the-road tests of Driving Impairment Monitoring (DIM) systems show that changes in driver state as measured by physiology (EEG) coincide with changes in steering performance and subjective ratings, while auditory warnings with respect to impaired driving performance were followed by increased driver effort and steering performance. Positive effects of feedback regarding distance keeping to a car-in-front were found in three on-the-road studies. Time-headways below one second were significantly reduced in case of tutoring. It was found that subjects have difficulty to estimate inter-vehicle distances expressed in time headway. Explicit recommendations to the driver with respect to appropriate time headway, e.g., by means of a bar that changes colour, is to be preferred. In a final on-the-road test of the integrated system, tag-vehicle communication was found to function at all speeds. Tutoring messages of the tutoring and enforcement system were found to have a beneficial effect on law-compliance. Most drivers accept these systems and consider them useful, although pleasentness-ratings are slightly negative. The factual introduction of in-vehicle enforcement systems has to deal with strict requirements of legitimacy of measurements. (A)
Abstract