Specifically, the proposed tunnel comprises twin-parallel bores, each possessing a diameter of 10 meters and separated by up to 70 meters; for safety reasons, connecting pedestrian passages between the two bores are to occur at regular intervals of up to 500 meters. This base tunnel, if built, is planned to enable trains to traverse the new route at a speed of up to 250 km/h. Being significantly faster than the Semmering line, it would enable a reduction in the travel time between the cities of Vienna and Graz.