Hindhead Tunnel

Hindhead twin-bore tunnel under the Devil’s Punch Bowl has removed a major source of congestion between Portsmouth and London.

The new 6km road includes a 2km stretch of tunnel. It was paramount that these tunnels remain operational 24 hours a day as the road is the major link connecting London to the south. During the planning phase, the highways agency identified that an advanced level of safety was needed in the tunnel area. A system was required to detect traffic incidents as they occurred. This was for two reasons: firstly, to ensure a timely response to assist people and vehicles stranded in the tunnel, and secondly, to avoid slow or stopped vehicle events escalating into major incidents as other road users become involved. Hindhead needed complete awareness of traffic flow and incidents in the tunnel at all times.

The solution needed to provide both high detection and low false alarm rates as this would keep the operator vigilant. The main issues that needed to be detected in the tunnel to maintain road users’ safety were stopped or slow vehicles, pedestrians in unauthorised areas, and debris. A further requirement was that detection performance should not be limited by environmental conditions and the ongoing performance of the system should not be dependent on regular, expensive routine maintenance, a feature that video analytic solutions are notorious for.