Pilot Project ASTRA Bridge for Traffic-Free Highway Maintenance

Maintenance work on highways with lane reductions can only be carried out at night on main routes. However, due to the constantly increasing traffic volume, the time windows for night work are becoming shorter. The Federal Roads Office (ASTRA) is addressing this issue, among other things, with a mobile construction bridge. The first deployment is planned for 2022. This would also be a relief for road freight transport.

(Bern) Lane reductions for maintenance work are no longer possible during the day on many highway sections due to current traffic levels. Accordingly, more and more construction work on national roads must be carried out at night. The necessary safety measures for construction workers must be set up every evening and dismantled again in the morning after the construction work. This is labor-intensive and shortens the time windows for the actual work. As traffic volume continues to increase at night, ASTRA assumes that in the future, lane reductions without traffic jams on the main routes (especially A1/A2) will only be possible after 11 PM. Due to lower noise limit values, some work is also not possible at night (e.g., noise-intensive demolition work). To counter these problems, ASTRA has decided to develop and construct the ASTRA Bridge.

Drive Above, Build Below

The ASTRA Bridge is a mobile bridge. It is built over the roadway to be renovated. Traffic is directed over it in two lanes. It is nearly 240 meters long and can be driven at 60 km/h. The access and exit ramps have a gradient of just over 6 percent. About 100 meters are available under the bridge for the actual construction work. The supply and disposal of the construction site is done via a logistics lane next to the ASTRA Bridge. Once the work under the bridge is completed, it is remotely controlled to move 100 meters further for the next construction phase.
The ASTRA Bridge not only ensures high traffic capacity. By spatially separating the construction site from the roadway, it increases safety for construction workers.
The ASTRA Bridge can be driven in two lanes at a speed of 60 km/h. As with other construction sites on the highway network, road users are urged to exercise special caution. If possible, they should drive staggered.

Current Status

The individual elements for the ASTRA Bridge are currently being built. The completed elements are transported by truck from the manufacturer to the designated storage location of the bridge in Rothrist (within the Wiggertal junction). The first parts arrived on July 26, 2021. By late autumn, all elements will be on-site and assembled for the first time so that the ASTRA Bridge can be tested as a whole.
The ASTRA Bridge prototype costs around 20 million Swiss francs and can be reused for the next construction project after the completion of a construction project and a maintenance phase.
If the tests are satisfactory, the ASTRA Bridge will be used in spring 2022 as a pilot project for surface renovations on the A1 section between Recherswil and Kriegstetten.
Photo/Video: © ASTRA