The study examines the impact of a new in-car navigation system on driver behaviour. A sample of 25 drivers was accompanied before, shortly after and 6 months after installation of the device in their cars. In all three phases they were navigated by the system from same origin to same destination. A modified version of the Vienna driving test was used to count driving errors, conflicts and exposure data. Shortly after installation, drivers behaved more safely than before, but once they had got used to the system and could anticipate what it was going to propose they returned to previous driving patterns. No long term, overall, safety impact could therefore be demonstrated. In another study, 18 drivers were accompanied by the same observer in unknown areas. The same data gathering logic was applied and situation-specific error rates for several driving manoeuvres were calculated. In comparison with well known routes, results show no decrease in driving performance with respect to error rates between intersections. This is interpreted as a gain in safety, since accident statistics show that driving in unkown areas is far more dangerous in terms of accident causation. Inside the intersections, error rates rose to the extent expected from accident investigations.
Abstract