Study on Lighting Optimization of Tunnel Entrance Section Based on Driver’s Visual Adaptation Model

The change of light intensity at the entrance of a tunnel, which causes the driver’s visual lag and the increase of reaction time, will affect the driving safety. Therefore, it is necessary to study the visual characteristics of tunnel drivers and put forward corresponding lighting optimization measures to improve the safety of tunnel operation. The illumination values at different sections of the tunnel entrance were collected during the vehicle test and the Sigmoid model of illumination changes at the tunnel entrance was constructed. Based on the Sigmoid model, the pupil area and illumination were analyzed by statistical methods and the visual adaptation model was established by polynomial-approximated approach. Finally, according to the present situation of tunnel lighting, optimization measures for transportation safety were put forward.