Evaluating safety effects of in-vehicle information systems : testing the method

Describes the test of a method proposed for assessing safety effects of modern in-vehicle information systems (IVIS). In the experiment, twelve subjects followed a prespecified, urban route using a map-based route guidance system. The entire route contained three instances of four common driving situations: turning right, negotiating general rule intersections, negotiating yield intersections, and driving straight ahead at major inner-city arteries. Safety was assessed by subjective ratings and objective measurements. The results showed that the subjective ratings were more sensitive to the effects of the route guidance system than the objective measures and that unsafe events occurred over twice as often with the guidance system than in a control condition. Safety reductions were found only with respect to braking and course keeping (control tasks) and not in the interaction with other traffic participants (manoeuvre tasks).