A driving simulator was used to model a winding road in which only narrow (1 degree vertically) segments of road edge were visible to the driver. It was found that with only one such region visible steering performance at slow speeds was as good as with the whole road visible, if the visible region was 7-8 degrees down from the horizon. At higher speed, however, this was not true, and two regions of road were necessary for performance as good as with the whole road. The far region, 2-4 degrees down, supplied information about road curvature, and the second region 7-8 degrees down provided feedback about the position of the vehicle in lane. These findings strongly support a two-component model of steering first proposed by Donges (1978), and argue against driver models that employ a single `preview' distance.
Samenvatting