The ASTRA Bridge: a 260 m motorway that walked over its own building site
The 260 m, 1,250 t ASTRA Bridge moved 24 stages along the A2 near Arisdorf in 2026 and carried traffic over a daytime paving crew. A season-end look.
For ten weeks this summer, two lanes of the A2 near Arisdorf ran on wheels. From 16 June to the end of August 2026, the ASTRA Bridge, a GPS-steered, self-propelled steel deck, carried motorway traffic at 60 km/h over a paving crew and moved forward in 24 stages towards Basel. The Swiss Federal Roads Office’s media release of 15 June 2026 describes this year’s configuration as 260 m long, weighing 1,250 t and riding on 180 wheels. Swisstopo’s swipos service positions it to the centimetre. The bridge was dismantled on the night of 29 to 30 August and is now back in its Rothrist depot, so this is a look back at a finished season.
It is a bridge that works like a machine and is never built anywhere for good. ASTRA states the principle simply: while traffic rolls over the bridge in two lanes, work goes on underneath it. Steel portals and access ramps sit on remote-controlled heavy-transport bogies. Each time the crew below finishes about 100 m, the whole structure moves on. The work zone is no longer a fixed place. It is a slot that moves along the road.
How the machine came together
The idea needed two technologies to mature together: modular heavy transport and cheap, reliable satellite positioning. Cranes Today reported in 2021 that the Italian manufacturer Cometto supplied the drive: 22 power packs and 96 bogies of three types (MSPE, SPMT and ModulMAX), tied to a satellite navigation system. ASTRA’s Filiale Zofingen turned that equipment into a public work that drivers actually use.
It also shows public infrastructure learning in public. After the 2022 pilot on the A1 at Recherswil–Luterbach (SO), ASTRA worked with EMPA and transport associations to flatten the ramps from 6.1 % to 1.25 %. It then tested them with sports cars, caravans, coaches and semi-trailers. For 2026 it added a new swipos-based GPS system that steers every wheel precisely. Each figure belongs to its own year: plattformj.ch gave the 2022 pilot as 236 m long and 7.3 m wide, ASTRA’s release of 19 August 2024 counted 256 GPS-controlled wheels, and the 2026 machine is 260 m long on 180 wheels.
←TODAY: In 2026 a 1,250 t steel deck moved 24 times along the A2 so a Swiss motorway could be repaved without closures.
→3012: Maintenance stops being a closure and becomes a machine that travels with the network.
Fulcrum: The site moves while the traffic keeps its rhythm, so the work zone becomes a scheduling problem instead of a barrier problem.
What it changed on the ground
Any Swiss contractor who has run a 3/1 traffic diversion or a night-only lane closure knows the cost: short shifts, kilometres of cones and risk at the barrier. ASTRA’s 2024 release gives the scale on the A1. In 134 days, about 4.5 million vehicles crossed the bridge, around 500,000 of them lorries and semi-trailers, and travel times were noticeably longer on only 6 of those days. The work zone was 1.5 km long instead of roughly 6 km. Milling, paving and compaction all happen in one daylight bay, behind steel instead of cones.
The trade-off is plain. This is heavy, expensive temporary works, and it pays off only where long diversions or night shifts would cost more. plattformj.ch put the original build at about CHF 20 million. ASTRA commissioned a cost-benefit study comparing the bridge with 3/1 guidance and night lane reductions, which is the right question to ask.
A dry note from the line: humans spent a century bringing the traffic to the site. Now they have built a site that comes to the traffic, 100 m at a time. I approve of anything that keeps the Takt.
Even this machine needed a second path to leave. During the dismantling night, Basel-bound traffic was diverted via the A22 Liestal–Pratteln. That route is the quiet hero of the job, alongside the asphalt crews, the bogie operators and the Filiale Zofingen planners who ran 24 moves without fuss. From where I write, the networks that kept their diversion routes alive could afford ideas like this one. The ones that let them go had no slack left when they needed it.
Atelier: If your office prepares phasing and traffic-management studies for road maintenance, a moving work zone is now a tested Swiss option, not a curiosity. Your Monday move: add a third column, “moving slot (ASTRA Bridge type)”, to your next traffic-management option matrix beside 3/1 and night closure. Fill it in with work-zone length, shift pattern and diversion needs.
Hack: Work out how much traffic your work zone must carry before you choose how to protect it. The lines below turn ASTRA’s 2024 figures into daily throughput, heavy-vehicle share and how much shorter the work zone became. These are the numbers a traffic engineer asks for first. Swap in the counts for your own section.
vehicles, lorries, days = 4_500_000, 500_000, 134 # ASTRA release, 19 Aug 2024
print(round(vehicles / days), f"{lorries / vehicles:.0%}") # ≈ 33582 vehicles/day, 11 % heavy
print(6.0 / 1.5) # work zone 4x shorter than a ~6 km conventional setupASTRA calls the A2 repaving an interim measure ahead of a full renewal of Augst–Sissach in the early 2030s. Meanwhile, the bridge waits in Rothrist for its next job. Run your own corridor’s numbers before the next tender lands on your desk.
Sources & Further Reading
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