Driving by night is known to be more dangerous than during daytime. In addition, a lot of drivers complain about vision during night driving. This is the first cause of driving restriction for seniors. The needs for lighting systems improvement concern safety and comfort. This relies on a certain knowledge about visual performance of the driver. The characteristics of the visual environment of night driving and the physiology of vision at low phototopic luminance level give clues to the improvements to reach. A specific experimental set-up was developed in order to measure the visual performance and fatigue while driving and without interrupting it. This test is based on the measure of visual acuity and contrast sensitivity. The visual fatigue is estimated from the evolution of the results to the tests versus time. Average drivers are asked to drive at early night (avoiding drowsiness) on open roads in order to compare several frontlight systems. Experiments lasted 3 hours of driving. Each driver tested three lighting systems, and then drove 9 hours in three nights. A classification of the systems is obtained in terms of visual performance of the drivers.
Abstract