The Bözberg Tunnel is a toll-free highway tunnel located in the northern part of Switzerland on the A3 motorway (from Basel to Sargans, mostly corresponding to National Road 3) between Basel and Zurich. It was put into operation in 1996, providing a direct alternative to the previously used Belchen Tunnel and enabling the bypass of Brugg. The planning of the Bözberg Tunnel began in the 1950s, and it was completed after about 8 years. The initial route includes crossing the Bözberg Pass and then the Aare Valley.
Since the existing Bözberg Tunnel did not meet the new clearance profile requirements (headroom of 4.0 meters), a new construction of the tunnel was necessary from May 2015 to May 2022. The project is estimated to have a volume of approximately 133.5 million EUR. The new tunnel, approximately 2,700 meters (2.7 km) long with two tubes spaced 30 to 50 meters apart, runs parallel to the existing railway tunnel.
The Bözberg Tunnel is approximately 2,500 meters (2.5 km) long.
The construction of the Bözberg Tunnel began in the early 1950s and took around 8 years to complete.
