The Katzenberg Tunnel is a railway tunnel on the Karlsruhe–Basel high-speed railway that opened in December 2012. The tunnel was built to increase the capacity and speed of the Mannheim–Karlsruhe–Basel railway and was built to remove the freight traffic from the towns on the old line. The two parallel, single-track tunnels, which can be passed at up to 250 km/h, extend from Bad Bellingen to Efringen-Kirchen With a length of 9,385 m, it is the third longest tunnel after the Landrücken Tunnel and the Münden Tunnel and the longest twin-bore tunnel in Germany.
The reduction in journey times for long distance passenger trains between Freiburg and Basel initially amounts to two minutes. After the completion of the entire section of line, the journey time will be around 15 minutes shorter.
Wikipedia https://en.wikipedia.org/wiki/Katzenberg_Tunnel
Coordinates 47°42'0.85" N 7°34'1.626" E