The Federal Roads Office of Switzerland created the ASTRA Bridge, an innovative approach to major road repairs that avoids requiring cars to make lengthy detours and allows traffic to pass over ongoing construction.
The ASTRA Bridge is a highly modular and movable structure that serves several purposes with a single design, making it comparable in adaptability to a Swiss Army knife. Highway road construction frequently closes many lanes and causes traffic jams, which is extremely inconvenient for drivers. Driver annoyance is increased when repair crews close off more comprehensive parts of the road for safety reasons rather than just the places they are explicitly working on. Long-term maintenance delays can cause whole sections of the road to become impassable, requiring travelers to find alternate routes and significantly increasing travel times.
The Swiss Federal Roads Office created the transportable ASTRA Bridge to solve this problem, which is advantageous to drivers and workers. Initial road closures are necessary for the ASTRA Bridge setup, often planned for the weekend when traffic is less. After that, trucks are used to move various bridge parts, which are put together overnight to form a flyover over the repair site.
The bridge, equipped with ramps on both sides, allows vehicles to quickly move up and down, bypassing the construction area without merging into a single lane. The current version of the ASTRA Bridge is slightly over 840 feet (257 meters) long and nearly 25 feet (7.57 meters) wide, supporting traffic flow over the repair site.
Vehicles using the ASTRA Bridge must travel at speeds of 37 miles (60 kilometers) per hour or lower. While this speed restriction is minor, taking detours or navigating congested lanes is preferable.
Beyond simply facilitating transportation, the bridge has several other advantages. It improves worker safety by freeing workers from having to keep an eye on approaching traffic and allowing them to concentrate entirely on their tasks. The bridge’s fifteen feet (4.65 meters) height allows for enough workspace below while shielding workers from the intense heat and rainfall. As a result, people who would often labor through the night are spared from hardship when roadworks are carried out during the day.
Shifting labor into the day reduces disturbances throughout the night, which benefits nearby neighbors. After a roadworks section is finished, hydraulic lifts raise the bridge just a bit, making it easy to proceed to the next repair part.
Early traffic flow problems were noticed during the ASTRA Bridge’s 2022 testing run on the A1. Improvements were made in collaboration with the Swiss Federal Laboratories for Materials Science and Technology (EMPA), one of which was to install ramps to lower the climb gradient from 6% to 1. 25%.
The bridge is a perfect solution for deployment anywhere roadwork is required because it can accommodate various vehicles, including trucks, semi-trailers, coaches, sports cars, and caravans.
