City officials in Sydney, Australia turned to an unusual technology to reduce the number of trucks that get stuck in the Sydney Harbour Tunnel. The new system projects a virtual image of a giant stop sign in front of the truck driver, just before entering the tunnel.
Besides the danger a truck getting stuck in the tunnel created for other drivers, repairing the tunnel after an accident could close this important passage for extended periods of time.
The city turned to Laservision and their Softstop system developed in 2011. When a vehicle too large to enter the tunnel is detected, a giant image of a stop sign is projected onto a thin layer or water at the entrance of the passage.
Sydney authorities say the new device is successfully activated 3-4 times per month on average. However, there are still some trucks that get stuck inside the tunnel from time to time.