Abstract
The role played by vision in highway safety cannot be adequately assessed from the isolated viewpoints of the doctor's consulting room, the psychological optics laboratory, the automotive design and engineering departments, the highway engineering department, or the regulatory agency. Efforts by automotive and highway engineers to improve a nonvisual clement of the vehicle and the highway have sometimes adversely affected the visual environment and efforts by eye doctors and vision scientists to improve the visual aspects of one of these man-vehicle-highway elements without considering its inter-relationships with the others may also affect the visual environment of each or any of these elements. Several examples follow.