Smart tunnel overview
Built on the Internet of Things, artificial intelligence, and big data, this solution covers highway tunnels, railway tunnels, and urban utility tunnels: structural health, the tunnel environment, ventilation and lighting, fire alarm, and traffic-event detection. Data from several sources drives linked control, so the lining stays sound, the air stays within limits, and traffic keeps moving, with less operating risk and less loss when something goes wrong.
A tunnel is a choke point: enclosed, long, and hard to leave. A fire, a crash, or a structural defect has serious consequences. China's Ministry of Transport requires key tunnels to be on a monitoring and control system. This solution covers structure, environment, equipment, and events. Settlement, crack, leakage, and lining-stress sensors watch the structure and warn early. CO, visibility, and wind speed drive the fans and the lights so driving stays safe. Fire detection combines heat and smoke, flame detectors, and video AI, and it calls the emergency broadcast, evacuation signs, and smoke exhaust. Video AI flags a stopped vehicle, wrong-way driving, debris, and a pedestrian in the bore, so the response starts quickly. It connects to the traffic monitoring center and the emergency command platform, for highway, railway, and urban tunnels.
Standards and technical requirements
Specifications for Design of Highway Tunnels (JTG D70) and Technical Specifications for Maintenance of Highway Tunnels (JTG H12) set requirements for monitoring, ventilation, lighting, and fire protection. Design Specifications for Highway Tunnel Monitoring Systems require a complete monitoring system in extra-long tunnels (over 3 km). Under the Ministry of Transport's Safe Transport program, key tunnels need full cover for structural health, the environment, fire alarm, and traffic-event detection. A smart tunnel has to do three things. Linked systems — a fire alarm starts smoke exhaust, lighting, broadcast, evacuation signs, and traffic control. Low latency — from detection to alarm, the response is within seconds. High reliability — the in-tunnel network is redundant, and critical equipment is on UPS.
Deployment notes
Where to place sensors: Structural points follow the geology, the lining type, and the history of defects. For an extra-long tunnel, a monitoring section every 500–1,000 meters is the usual recommendation. CO and visibility points follow the ventilation zones. Cameras are typically 50–150 meters apart, with tunnel lighting and fill light taken into account.
Communications: Inside the bore, fiber plus industrial Ethernet is the usual choice, because radio fades badly. Video and sensor data are gathered at the edge and then sent up. Plan redundant paths at the portals and between sections inside the tunnel.
