A simulator experiment was conducted to investigate the effects of restricted visibility in fog on individual longitudinal driving behaviour on motorways. The experiment served partly to verify the findings of an analysis of inductive loop detector data, and partly to acquire additional knowledge. Aspects of driving behaviour studied were free driving (speed choice), car following (following distance, headway), and approaching slower lead vehicles. The main experimental conditions were visibility distance (40, 80, 120, and 600 m), light condition (day/night), and driving instruction (normal/hasty driving). The results of the simulator study had a good resemblance with real-world loop detector data. The main effect of fog on driving behaviour is a reduction in free-driving speeds, although in real-world conditions this reduction is insufficient to allow for a successful stop for a stationary obstacle. An effect of visibility distance on following distance or headway has not been found. (A) See also IRRD 898627.
Abstract