Study on Design of Dimming Structure and Tunnel Lighting of SZCST

Due to its special geographical location, the brightness outside the Shenzhen Zhongshan cross sea tunnel(SZCST) is too strong. A large difference in brightness inside and outside the tunnel can cause driver discomfort and affect driving safety. This paper firstly analyzes the necessity of the dimming structure according to the collected data of brightness outside the SZCST. Then a mathematical model of the reduction coefficient and the small target recognition distance is obtained based the target recognition experiment. Based on the model, the brightness and length of the dimming structure outside the tunnel are determined. In addition, in order to have a smooth transition of brightness inside and outside the tunnel, a gradual arrangement of lighting lamps is proposed to provide driver a better human visual environment. Besides providing drivers to smooth brightness environment, another benefit of building a dimming structure is reducing the design brightness inside the tunnel, thereby greatly reducing energy consumption and operating costs of the tunnel.