The light source of tunnel lighting should meet the requirements of light efficiency, light flux, life span, light color and color rendering under the specific environment of the tunnel, and at the same time, it should ensure good visibility in the smoke caused by automobile emission. The tunnel lighting effect must rely on the reliable light source to achieve. Once the highway tunnel is put into use, the lighting system is almost in the state of long-term lighting under the normal state. Therefore, the selection of an appropriate light source is an important part of tunnel lighting. Tunnel lighting requirements…