In the absolute worst-case scenario, the high-pressure spray mist system provides fire protection.
The high-pressure jets (around 55 bar) distribute spray mist in the tunnel. This produces water mist, which prevents the high temperature from spreading and protects road users and the tunnel structure itself. This automated system keeps the high temperatures in check until the fire department arrives. This is an important first step for preventing the fire from spreading in the tunnel.
High-pressure spray mist systems are currently in use in the following tunnels:
- A1 West motorway: Liefering Tunnel
- A 14 Rheintal/Walgau motorway: City Tunnel
Plans are in place to install a spray mist system in the Arlberg Tunnel at S 16 of the Arlberg expressway and in the Wald Tunnel on the A 9 Pyhrn motorway.