Upgrading existing TERN road tunnels to current needs. Taking the Arlbergtunnel as an example: Fid-Bau Portal

Upgrading existing TERN road tunnels to current needs. Taking the Arlbergtunnel as an example

Bacher, M. / Sturm, P.J.

The operation and safety facilities of European road tunnels in the Trans-European Road Network (TERN) must meet the requirements of Directive 2004/54/EC by not later than April 2019. This regulation applies to all tunnels in the TERN with a length of more than 500 metres, whether they are in operation, under construction or under design. This directive aims at ensuring a minimum level of safety for road users by preventing events which might endanger human life, the environment and tunnel installations. Taking the Arlberg road tunnel as an example, this paper shows how an existing road tunnel may be upgraded to meet the requirements of Directive 2004/54/EC and the Austrian national guidelines RVS. The Arlberg road tunnel is the longest single-tube road tunnel in Austria, and has a relatively low traffic volume. Hence, the construction of a second tube is not really cost effective. As this tunnel is the only winter-safe link between Tyrol and Vorarlberg, the closure of the tunnel during winter needs to be avoided as far as possible. A feasibility study including 5 options for upgrading the tunnel was performed. The feasibility study showed that the construction of a second tube for unidirectional traffic (option 5) or the construction of a new bi-directional tube - using the existing tube as escape and rescue tunnel (option 4) - is not suitable due to the low traffic volume and the length of the tunnel. Option 1 requires too many tunnel closures and the loss of toll income is too high. Option 2 was not found to be acceptable due to the high safety risks arising during the construction time. Therefore option 3 was selected for realisation. This option has a relatively short construction time and is also to be recommended from an economic and technical point of view. The Arlberg road tunnel has a full transverse ventilation system. In order to minimize construction costs the fresh air duct will be used as an egress way. Construction of long crosspassages to the parallel railway tunnel can thus be avoided. In the case of fire tunnel users can reach the fresh air duct (safe area) via ramps from the traffic room. From the fresh air duct the egress ways lead to existing collecting rooms, from where the tunnel users can be evacuated through the railway tunnel. In order to protect the fresh air duct against high temperature, fixed fire fighting systems will be installed in the traffic room. In addition, complete replacement of all the safety equipment is to be carried out.