Lustenau-Au bridge could face full closure as lifespan ends

The Rhine bridge between Lustenau and Au could be fully closed as authorities assess its future, ORF Vorarlberg reports. The bridge is due to reach the end of its technical service life next year, 70 years after it was built.

The state of Vorarlberg and the Swiss canton of St. Gallen have commissioned a cross-border planning study to examine possible measures, including a complete closure. State deputy governor Christof Bitschi, who is responsible for road construction and transport, said he plans to present details in November.

The authorities say the bridge remains safe and its condition has not worsened. Sensors have monitored it continuously since June 2023. A heavy truck can cause the structure to bend by up to five centimetres at its midpoint. A 2025 traffic count recorded more than 14,500 vehicles crossing each day.

Built in 1957, the bridge was among the first prestressed concrete bridges in Austria and Switzerland. Vorarlberg owns 56 percent of it and the canton of St. Gallen owns 44 percent. Both communities on the Rhine initially opposed the bridge, but their governments went ahead with the project.

Bitschi said the end of a bridge’s technical service life does not mean it is about to fail. He expects the bridge could remain usable until 2033 or 2034, but said there was no guarantee. If its condition deteriorates, options could include renewed weight limits for heavy vehicles, a one-lane arrangement or a full closure. Each could affect traffic, with a closure shifting vehicles to nearby communities.

The planning work has not yet begun. It is also expected to assess critical junctions on diversion routes and the effects on public transport, including possible changes to routes and timetables. Vorarlberg has more than 600 bridges, many built during the construction boom from the 1950s to the 1980s and now facing rising maintenance costs.