Abstract
In this study, visibility of a driver on a highway was more severely degraded, the driver being allowed only a small area of the road by which to drive. Velocity selection was found to be a function of distance to available information and velocity maintenance of the angle of information. Lamps located about 75 feet away produced the lowest variability in velocity and steering-wheel movements and the highest average velocity. Whereas lane markers were used for tracking because of their high contrast, there was no tendency toward tracking on unlined roads regardless of lamp placement.