Milestone on the A1: mammoth Aurach Bridge project successfully moved into end position

Location: Regau, Vöcklabruck district
Client: ASFINAG
Total cost: approx. 65 Mio. €
Length of bridge: 420 m
Height of bridge: 50 m
Bridge surface area: approx. 12.600 m2
Concrete installed: approx. 30.000 m3
Construction start: August 2022
Overall completion: End of 2025

On 14 May, the HABAU GROUP, PORR and ASFINAG celebrated the transverse moving of the highest bridge on the A1 West Autobahn. 

 

Since summer 2022, the consortium made up of the HABAU GROUP and PORR, on behalf of ASFINAG, has been establishing an infrastructure project of extraordinary dimensions near the Regau junction in Upper Austria: the total demolition and reconstruction of the Aurach Bridge, which at 50 metres is the highest bridge on the A1 West Autobahn. After more than 60 years of continuous operation, the existing support structure from the 40s and 60s had reached the end of its service life. Around 50,000 vehicles cross the bridge each day, with this load climbing considerably higher in the summer months. Due to its age, the increased traffic frequency and today’s safety and structural requirements, the bridge is being rebuilt. On 14 May, as part of a festive ceremony, the transverse shifting of the 15,000-tonne support structure into its end position took place.

 

“The successful transverse moving of the new Aurach Bridge is a technical milestone and shows once again what is possible with coordinated teamwork and elite engineering skill. A project of this magnitude can only be pulled off when everyone works together,” says Hubert Wetschnig, CEO of the HABAU GROUP. “As the HABAU GROUP, we’re very pleased to be able to play a part in such a significant infrastructure project and would like to thank our client and consortium partner for the collaborative and construction cooperation.”

 

420 metres of precision work: an overview of the large-scale project

With a length of 420 metres and a height of 50 metres, the new bridge traverses the Aurach Valley in the Vöcklabruck district. To establish the supporting structure, what is known as the balanced cantilever construction method was applied – a demanding method that requires the utmost precision. The new support structure for the Salzburg carriageway was completed in the lateral position in late 2023. After demolition of the old existing structure, the support structure for the Vienna carriageway was finalised in April 2025.

 

The dimensions of the construction project are huge: a total of roughly 30,000 cubic metres of concrete, 3,600 tonnes of reinforcing steel and 305 tonnes of prestressing steel were installed. The new bridge has a surface area of around 12,600 square metres. And even individual steel girders weighing up to 230 tonnes were lifted off with the help of a 1,000-tonne crawler crane – a logistical master stroke.

 

Alongside the structural and technical complexity, the extremely tight construction time was a critical factor above all. To cause as little impairment as possible to the heavily frequented A1, the support structure for the Salzburg carriageway was first erected in the lateral position on temporary abutments, on which all traffic is guided on two lanes. This provisional solution enabled the largely hassle-free execution of the project despite a high traffic load.

 

Technical highlight and sustainability

The project is setting new standards in terms of sustainability too: around 130,000 tonnes of concrete material was removed during the demolition of the old support structure; this was then recycled in full and used, for example, as bulk material in road building. In addition, as part of renaturation over an area of two hectares, the construction site will be planted with around 4,000 new trees.

 

A pivotal moment in the project was the so-called transverse shifting on 14 May 2025: the support structure for the Salzburg carriageway, weighing around 15,000 tonnes, was transferred onto a total of 24 sliding carriages and, with the help of twelve strand jacks, was shifted approx. 15 metres into the end position using a specially constructed skidway – a technical feat of strength and a crucial milestone in the course of the project. Overall completion of the project is planned for the end of 2025.