ROAD LIGHTING FOR AGEING DRIVERS - A USERS' PERSPECTIVE

To get a feeling for the decline in visual performance in ageing drivers, a target visibility experiment was carried out with a group of drivers aged around 70 years. Visual performance shows a large variation in this group of ageing drivers. It seems that most of the decline is in the mental processes, including vision, and not so much in the motor processes. At a visibility level >= 11, most of our subjects are able to react within the required 1.5 second and the majority shows only the occasional false negative response. Age in itself is no measure for the visual performance of the visual system. The visibility level as calculated using the model of Adrian, ignoring the age factor, seems to be useable. On the majority of the calculation grid points, the majority of our test subjects would not be able to see a small object in time.