The 13km section starts at the end of the existing four-track Graz - Feldkirchen line and joins the operational part of the Koralm railway at Werndorf. The new section includes a 3.2km underground section close to Graz airport, which will be built in open cast method. There will also be six railway bridges and six road bridges along this section.

The railway will be completed in 2023 with technical equipment to be completed in 2025 when the complete Koralm railway is scheduled to open.