The Lion Rock Tunnel is duel-bound tunnel, which connecting Sha Tin in the New Territories and Kowloon near Kowloon Tong. The daily total throughput is approximately 90,000 vehicles in 2000. In order to avoid the hazardous‘black hole’effect of drivers, ensuring that illumination in a tunnel entrance is continuously changed automatically to match the changes of exterior daytime brightness is very important. Fixed luminance photometers were mounted at exterior of tunnel. After calculating the data of luminosity by PLC, several stages of illumination could be output for providing continuously changes of illumination.

Second Lion Rock Tunnel

Lighting System Control Panel

System Structure


A.B.PlC