This report describes three studies on the effects of road, weather, and traffic conditions on individual driver behaviour. Road type and friction under normal driving conditions were studied by tests with subjects on a variety of roads. A quantification of strain by psychological and psycho-physical data identifies three separate driver types. Visibility was studied by analyzing inductive loop data combined with visibility measurements, and by a driving simulator study on behaviour in fog under controlled experimental conditions. Visibility range has distinct effects on free speeds. No separate effect of fog on either following distance or headway appears to be present. Time-to-collision values tend to increase. A desk study into the behaviour of drivers of various types of vehicles in cross-wind conditions resulted in satisfactory lateral control model of car and truck drivers. A lack of knowledge exists on dynamic motor-cycle rider response to cross-wind.
Abstract