Bosch Signalbau Huber AG has installed a comprehensive and sophisticated tunnel control system in Guangzhou, China, for the Pearl River Tunnel Company. It has three bores, one for an underground railway, and the other two for two road traffic lanes in each direction. The total tunnel length is 830m. The operators of the system use computer terminals to control and monitor everything from lighting and emission levels to security and traffic flow. Carbon monoxide (CO) and visibility detectors measure exhaust emissions, and jet fans are switched on when they exceed given limits. Intelligent lighting control allows drivers to adapt smoothly from outside brightness to light conditions in the tunnel. Closed circuit television (CCTV) handles safety, security, and emergency functions, and drivers can also use emergency telephones. Each terminal uses a visual display map with coloured symbols to indicate the current status of signals, sensors, fans, etc. Only one task is displayed at a time, to make the operator's work easier. An advanced wall map display provides an overview of the tunnel. Traffic control and traffic signal programmes for the three tubes can be selected together or separately. The centre's computer system has three stages.
Abstract