Together with its partners, ILF Consulting Engineers was commissioned by Autobahndirektion Südbayern (motorway authority of Southern Bavaria) to carry out the site supervision of the new construction of the B2 federal road on the Oberau Nord section to Ronetsbach including the Oberau tunnel.
The approx. 2.9 km long Oberau tunnel comprises the key element of the 4-lane expansion of the federal road and of the Oberau bypass. Due to the high traffic volume the tunnel is constructed as a two-bore traffic tunnel, each bore having 2 lanes in one direction, incl. lay-bys; the tunnel runs approx. 83 % in hard rock and approx. 17% in loose rock.