Kombilösung Karlsruhe

At the end of 2021, after 12 years of construction, the Kombilösung - Karlsruhe was opened.
Part of the Kombilösung is the new light rail tunnel with a total of 7 underground stops at a depth of up to 13m. Event ventilation by means of exhaust air axial fans was installed at four stops.
- Main tunnel 2.4km long under Kaiserstraße with 4 new stops
- South branch 1km long with 3 additional stops