Road construction projects can be a massive pain in the butt. Roads either end up closed, or they go down to a single lane, and it takes an age to get anywhere. But what if you could simply drive over the construction as if everything was virtually normal? That’s precisely what they’re doing over in Switzerland.
This topic came to our attention via Conflict on Twitter. A video sourced from Swiss authorities showed us how road authorities get the job done over there. The basic concept is simple: Instead of blocking off an entire road, or squeezing traffic past the workers, just let motorists drive over the top instead!
Right away, the benefits are obvious. Work on the roadway can go on undisturbed. Road crews don’t have to worry about speeding cars flying by mere feet away from their operations. Meanwhile, it’s better for traffic too—there’s no need to slow to a crawl or find a detour. They can just take the high road to get where they’re going!
???? İsviçre'de yol çalışmaları esnasında kullanılan mobil bir üst geçit. pic.twitter.com/yC0o2Gjm08
— Conflict (@ConflictTR) August 17, 2024
How It Works
If you’ve never seen this before, that’s because it’s a very new invention. It was the brainchild of the Swiss Federal Roads Office (FEDRO), which calls it the ASTRA Bridge.
The bridge is installed using trucks and cranes ahead of repair works on a given stretch of road. Road workers start by building a temporary raised structure over the area to be repaired or resurfaced. It’s basically a bridge over the existing road, built in sections that are wheeled into place as needed. The structure is high enough for work vehicles to pass underneath.
The bridge provides a working area a full 16.7 feet (5.1 m) wide and 10.2 feet (3.1 m) high. Most importantly, there’s enough room for the asphalt layers, steam rollers, and various support vehicles to do their work beneath the temporary raised roadway. Flex between the individual sections of the roadway is enough to accommodate a minimum bend radius of 1000 meters (0.62 miles) which is enough to deal with most stretches of motorway.
Sections of the roadway are joined with a pin-and-tab system. Hydraulic rams in each section push a pin through a tab in a dongle hanging off the next section.
Even better, each section has wheels and hydraulic lifts. Big assembled sections of the bridge can be raised off the ground and rolled along as needed to get them in the right place. Have you ever seen a bridge move? Watch the video above and you can say you have.
Other than the traffic roaring overhead, the works underneath proceed the same as any other road resurfacing operation. Of course, there’s one additional benefit—the temporary structure provides a small measure of protection from any rain overhead, too. It also eliminates the need to work at night to avoid excessively delaying traffic, with the benefit of less after-dark noise pollution for residents living nearby.
The ASTRA bridge was first trialed in 2022 and was used for work on the A1 highway between Recherswil and Luterbach. Initial results were favorable, with a smooth setup and packdown with no vehicle accidents on the bridge. However, initial traffic flows weren’t as great as desired.
Revisions were later made to reduce the gradient of the bridge from 6.1% down to just 1.25%. This allowed vehicles to more easily traverse the bridge at a speed of 60 km/h (37 mph). FEDRO tested the new design with sports cars, caravans, buses, trucks, and semi-trucks in order to make sure all traffic could safely use the temporary structure.
The most recent deployment has seen the ASTRA bridge once more deployed on the A1. It was assembled in April over two nights, and is expected to remain in place until at least the end of August as works are ongoing.
Construction was handled primarily at night.
If you’re currently tangling with roadworks in your local area, you can probably see the value in this system. While it’s probably not of huge use in crowded downtown areas, it could be a huge boon on many larger roads, highways, and motorways. Expect other transport authorities to look closely at what’s going on in Switzerland, because this idea is too genius to ignore.
Image credits: FEDRO, YouTube screenshot via Federal Roads Office FEDRO (Switzerland)
Impressive engineering! But how long does the staging take and at what cost? It’s a lot of manpower to get all the ASTRA components needed to the site and properly elevated, connected and set up to handle traffic. I can’t think of a situation where this would be preferrable to the SOP of just doing the work at night with some temp barriers and caution signs.
Depends which costs are being factored in and what alternative routes are available. In this case, there are often no other roads nearby and there is a barrier on each side of the road, making a diversion impossible. And it is faster than blocking a single lane
I have to admit I would love to see this in the US or Canada sometime soon!
Steam Rollers? those went out of fashion pre WW2, nowadays they are just called Rollers
This is so very Swiss. No expense spared, on anything.
These would be wonderful here in Winnipeg, where our method of road construction is “close off lanes on every vital route in town simultaneously” in a city that’s cut off by rivers and railway underpasses. We also don’t have any work happening overnight and very rarely have road/utility work on weekends except for emergencies like water main or sewer breaks.
Well tab my dongle and call me Swiss!
I can’t imagine how much this thing cost….
Inner 8yo triggered: That is so COOL!
A lot depends on alternate routes. This is a complex, expensive solution to what is often minimal inconvenience/disruption.
That’s crazy. I wonder how long it takes to move it? Side to side should be pretty quick but moving down the road has to take a lot more time. As far as being tall enough for the construction equipment I’d say that the operator of the paving machine wouldn’t agree, since he has to duck under the cross-beams every so often.
This summer the WA DOT has been big into complete closures of some pretty highly traveled freeways. Most of them have just been over night but we’ve had a few weekend long ones too.
Last weekend had a bunch of them including a weekend long on my route last Sunday. I got on at the first open entrace after the closed section. It was weird being on a basically empty freeway that would normally be packed any time of day.
Agree.
Feels a tad bit post apocalyptic that.
Yeah I think WSDOT just got a bunch of road maintenance funding. It is a bit aggravating though when you have like 3 major roads closed down.
But whoever runs their social media needs a raise.
Well 405 has been the subject of a lot of those closures due to the widening project and of course they are trying to get in as much work as possible before the rains set it for good. But yeah it was definitely a you can’t get there from here weekend with 3 major closures.
I’m in love!
When I was working in a town called Baden in Switzerland I watched a bridge being repaved. It was over the Limmat river that separates Baden and Wettingen. I had NEVER witnessed such extreme care and precision on a road repair, and it was not only precisely and masterfully executed, it also only took a week. Maybe two tops. And this was a bridge that still had traffic on it, as it was really the only way to cross the river. Got to hand it to the Swiss. Their stereotypes hold up.
Driven over them. Can confirm it’s actually fun