The ASTRA Bridge, developed by the Federal Roads Office of the Swiss government, offers an innovative solution to alleviate the disruptions caused by highway road repairs. This highly mobile and modular structure functions like a Swiss Army knife, providing multiple benefits in a single design.

Highway roadworks often frustrate drivers by closing multiple lanes, creating traffic bottlenecks, and reducing overall traffic speed. For safety, repair teams usually close off more lanes than necessary, further compounding driver inconvenience. Prolonging repairs can make entire road stretches off-limits, forcing drivers onto lengthy detours and increasing travel times.

Enter the ASTRA Bridge. This mobile bridge allows traffic to flow smoothly over ongoing road repairs, benefiting both drivers and workers. Setting up the ASTRA Bridge does require a temporary road closure, ideally over a weekend when traffic is lighter. Once the closure is in place, sections of the bridge are brought in on trucks and assembled overnight, creating a flyover above the work zone. Ramps on both ends facilitate vehicle movement up and down the structure without hassle.

The current ASTRA Bridge spans over 840 feet (257 meters) long and nearly 25 feet (7.57 meters) wide, allowing vehicles to bypass the repair area without merging into a single lane. Vehicles using the bridge must travel at speeds of 37 miles (60 kilometers) per hour or lower—a small price to pay compared to taking a detour or getting stuck in traffic.

Benefits of the ASTRA Bridge

The advantages of the ASTRA Bridge extend beyond the motorists who use it. With traffic flowing above, workers can focus on repairs without the constant concern of oncoming traffic. The 15-foot (4.65 meters) tall structure provides ample space for workers to operate underneath while offering protection from heat and rain. Daytime work becomes feasible, reducing the strain on workers who would otherwise work through the night. This shift also benefits nearby residents, as nighttime noise disruptions are minimized.

When a section of work is completed, hydraulic lifts raise the bridge slightly, allowing it to be moved forward to the next work area. The ASTRA Bridge’s adaptability was demonstrated in 2022 during its first trial on the A1 highway. While initial traffic flow was uneven, improvements were made in collaboration with the Swiss Federal Laboratories for Materials Science and Technology (EMPA). The addition of ramps reduced the climb gradient from six percent to 1.25 percent, enhancing vehicle transition.

The bridge is compatible with various vehicles, including caravans, sports cars, coaches, trucks, and semi-trailers, making it ideal for deployment in diverse road repair scenarios.

The ASTRA Bridge represents a significant leap forward in road repair technology, ensuring smoother traffic flow, enhanced safety, and more efficient repair processes, all while reducing the inconvenience for drivers and the workload for repair crews.

By Impact Lab