Switzerland Found A Wild Way To Repair Highways Without Stopping Traffic

Road construction usually comes with one unavoidable promise: slow down, change lanes, or prepare to sit in traffic. Switzerland has found a way around that problem, and the solution looks so strange that people online have started joking that the country is already living in 2050. The machine behind the reaction is the ASTRA Bridge, a 257-metre mobile structure that allows traffic to pass over sections of motorway while workers repair the road underneath.

The enormous structure is already being used on Swiss highways, and its latest version has been upgraded after an awkward first attempt. Instead of shutting down lanes and sending drivers through lengthy diversions, Switzerland has created a moving construction platform that allows the road above and the work below to operate at the same time.

The Bridge Lets Traffic Pass Above Active Roadworks

The basic idea behind the ASTRA Bridge is surprisingly simple, even though the engineering involved is anything but. Instead of closing a section of motorway and forcing drivers through a conventional construction zone, the structure creates a temporary elevated road above the work area, allowing cars and trucks to continue moving while crews repair the highway beneath them.

The bridge weighs around 1,250 tonnes and stretches roughly 257 metres. It is equipped with hundreds of wheels, multiple motors and a hydraulic system that allows the enormous machine to move along the motorway. In practice, it functions less like a conventional bridge and more like a giant construction vehicle that carries two lanes of traffic.

The Swiss Federal Roads Office developed the system specifically for motorway maintenance.

Its purpose is to separate drivers from workers while allowing repairs to continue during the day, reducing the need for lengthy closures, diversions and overnight construction.

That separation also creates a shorter construction zone. According to the supplied reference material, conventional traffic management could require a work zone of around six kilometres, while the ASTRA Bridge reduced the affected stretch to roughly 1.5 kilometres during its 2024 operation.

For motorists, that difference can be significant. A construction project may occupy a huge stretch of motorway because of safety buffers, lane changes and traffic-management requirements, even when the actual repair work is taking place across a much smaller area.

The First Version Had a Serious Problem

The ASTRA Bridge did not immediately become the futuristic success story now circulating online. Its first major use took place on the A1 motorway between Recherswil and Luterbach in 2022, where engineers were able to demonstrate that the basic concept worked and that repairs could be carried out beneath the structure while vehicles travelled above it.

However, traffic flow was not as smooth as engineers had hoped. The ramps leading onto and off the bridge were too steep, which forced vehicles to slow considerably as they climbed onto the temporary roadway and descended on the other side. Heavy goods vehicle operators also reportedly complained about the bumpy ride.

The problems became serious enough that the project was criticised publicly. One Swiss haulage contractor and parliamentarian described the first deployment as a “debacle,” according to the supplied reference reporting from NZZ, raising questions about whether the expensive experiment would actually become useful.

Instead of abandoning the idea, Swiss engineers went back to work. The bridge was redesigned, with the access ramps lengthened and their gradient dramatically reduced from 6.1% to 1.25%, addressing one of the biggest complaints from the first deployment.

The improved structure was then tested with a wide variety of vehicles, including sports cars, coaches, caravan trailers, lorries and semi-trailers. The Swiss Federal Roads Office reported that all of them were able to cross the bridge at 60 km/h without difficulty, suggesting the redesigned version was far more practical for everyday motorway traffic.

Engineers Made the Giant Structure Easier to Control

The most impressive part of the ASTRA Bridge may not be its size. The real engineering challenge lies in making a 1,250-tonne structure behave like a usable section of motorway while allowing construction crews to work underneath it.

The bridge consists of modular sections and can be assembled on the motorway over two consecutive nights. The operation requires low-loader trucks and pneumatic cranes, so putting the machine into position is itself a major logistical exercise that has to be carefully planned around traffic.

Once assembled, however, the structure can be controlled remotely. The bridge has 22 power packs connected to one another, allowing the entire unit to be moved, steered and stopped using a single radio remote control.

Joachim Kolb, sales manager at Cometto, one of the companies involved in the project, explained the system by saying, “This makes it possible to move, steer, and stop this huge unit with just one radio remote control.”

The machine can then advance through the construction zone as work progresses. Crews repair one section underneath the bridge, complete the required work and then move the structure forward to create the next working area.

The working area beneath the bridge is around 100 metres long. That means a long stretch of motorway maintenance can be broken into manageable stages without requiring the entire road to become one continuous construction zone.

Millions Of Vehicles Have Already Crossed It

The technology has now moved well beyond a laboratory experiment. The improved ASTRA Bridge returned to the A1 in 2024, where it carried a substantial amount of traffic during the construction season.

According to the supplied reference material, around 4.5 million vehicles crossed the mobile bridge during its 2024 season, including roughly 500,000 trucks. The Swiss Federal Roads Office reported that traffic flow was barely affected during the operation.

The improvement was particularly important because the bridge did not simply provide an unusual way for vehicles to cross a construction site. It changed the size of the construction zone itself, reducing the section affected by traffic management from around six kilometres to approximately 1.5 kilometres.

For drivers, the result is easier to understand than the engineering specifications. Instead of travelling through a long sequence of narrowed lanes and construction barriers, motorists encounter a much shorter section where they climb onto the temporary roadway and continue above the workers.

The bridge does still require drivers to slow down. Its operating speed is around 60 km/h, so it does not make the construction zone disappear from the driver’s journey. What it does is keep the motorway functioning while the actual repair work continues underneath.

The Bridge Is Designed Around Worker Safety

Traffic management is only part of the reason Switzerland developed the ASTRA Bridge. The other major concern is the safety of people working on the motorway.

Traditional road construction can put workers dangerously close to vehicles travelling at high speeds. Even when barriers and warning systems are in place, construction crews can spend hours working beside moving traffic.

The ASTRA Bridge physically separates the two groups. Workers carry out repairs underneath the structure while vehicles pass overhead, removing the need for traffic to drive directly beside the work area.

Jürg Merian, the project manager associated with the system, stressed the difference by saying, “The hazard potential for the construction workers involved has been lowered enormously because the traffic no longer has to drive by them.”

The structure also provides workers with protection from weather. Rain and direct sunlight can interrupt outdoor construction, while the enclosed working area beneath the bridge offers a degree of shelter that ordinary motorway repairs cannot provide.

The change in working hours is another advantage. Noisy activities such as milling and road resurfacing can be performed during the day rather than being pushed into the night because of traffic demands.

That could make a difference for people living near major motorways. Fewer overnight construction operations mean less disruption for nearby residents, while construction crews can work during more conventional hours.

Switzerland Is Using It Again In 2026

Switzerland has not treated the ASTRA Bridge as a one-off experiment. The latest version is being used on the A2 between Arisdorf and Giebenach in 2026, where crews are working on more than five kilometres of road surface.

The current operation is expected to progress through around 50 stages. As each section is repaired, the mobile bridge can move along the motorway and create the next work area, while traffic continues above the repairs at around 60 km/h.

The latest version has also received additional upgrades. These include a GPS system intended to control its 180 wheels more precisely as the enormous structure moves along the motorway.

That detail gives some idea of how complicated the machine really is. Moving a normal vehicle along a road is relatively straightforward, but moving a 1,250-tonne structure carrying live motorway traffic requires far greater precision.

The bridge has to remain aligned with the road while moving between construction sections. It also needs to accommodate different types of vehicles and the changing conditions of an active motorway worksite.

The goal is to make that complexity almost invisible to motorists. From behind the wheel, drivers should simply see a temporary road ahead, follow it and continue their journey.

The Technology Could Change How Road Repairs Are Scheduled

The ASTRA Bridge also addresses a problem that has frustrated road authorities for decades: when should major maintenance actually take place?

Busy motorways often cannot be closed during the day without creating major congestion. That can force construction crews to work at night or during weekends, creating additional noise and making the work schedule more dependent on traffic conditions.

Weather can complicate the situation further. Road resurfacing and other maintenance work can be affected by wet or frosty conditions, which is one reason why certain repairs are concentrated into warmer months.

The mobile bridge changes the calculation by allowing workers to operate underneath active traffic. The motorway does not have to become completely unavailable simply because a section needs repairs.

According to the Swiss Federal Roads Office, the system can also be used for work beyond ordinary resurfacing, including bridge repairs and replacement of road expansion joints. That gives the technology potential applications beyond fixing damaged asphalt.

There are still limitations, however. The bridge requires a major logistical operation to assemble and dismantle, and its development has been expensive. The original version also needed significant redesign after the problems encountered during its first deployment in 2022.

Reference reporting puts the initial development and construction cost at around CHF20 million, with approximately CHF5 million spent on optimisation after the first attempt. That is a substantial investment for a single piece of road-maintenance equipment.

The Swiss approach is therefore less about finding a cheap replacement for traditional roadworks and more about finding a way to reduce disruption on heavily used motorways.

Other Countries Are Already Watching

The unusual machine has attracted attention outside Switzerland as well. According to the supplied reference material, authorities from almost 20 countries have made enquiries about the technology, with Norway reportedly expressing interest in renting the bridge.

Inquiries have also reportedly come from countries including Japan and the Netherlands. That interest suggests Switzerland’s problem is far from unique.

Modern road networks are expected to carry huge volumes of traffic while also requiring constant maintenance. Closing major routes can create congestion far beyond the construction site itself, especially when drivers are forced onto smaller surface roads.

Every country has different road designs, traffic patterns and construction standards, so the ASTRA Bridge may not be suitable everywhere. The cost and logistics involved would also need to be considered before another country could adopt the system.

The underlying idea is easier to transfer, though. Instead of forcing traffic to stop whenever major road repairs begin, engineers can create a temporary route that allows vehicles and construction crews to occupy the same stretch of motorway without sharing the same physical space.

That could become increasingly useful as aging road infrastructure requires more frequent maintenance.

The Strange-Looking Bridge Is Already Proving Its Worth

The ASTRA Bridge looks almost ridiculous the first time someone sees it. A huge metal structure stretches along the motorway, cars climb a ramp and disappear onto an elevated roadway, while construction workers repair the road beneath them.

Then the entire structure moves forward.

That visual is probably one reason videos of the system have attracted so much attention online. Most people are accustomed to roadworks behaving in the opposite way. Barriers appear, lanes disappear and traffic becomes the thing that has to adapt.

The ASTRA Bridge reverses that arrangement. The construction site becomes the moving element, while traffic continues along a temporary roadway above it.

The technology still has limitations, and Switzerland had to learn from the problems encountered during its first deployment. But the improved version has already carried millions of vehicles, while allowing workers to repair the motorway beneath it.

That makes the viral “living in 2050” jokes a little easier to understand. Switzerland has not eliminated road construction or invented a motorway that repairs itself. It has simply found a remarkably unusual way to keep the road open while the work happens underneath.

For drivers stuck behind miles of conventional roadworks elsewhere, that may be the most futuristic part of the whole idea.