In Austria, the Koralmbahn rail link between Graz and Klagenfurt is approaching operational readiness, with commissioning set for 14 December 2025.
Before regular passenger services begin, the line will undergo an extensive programme of testing, training, and safety checks.
From 14 April, test and measurement runs will begin along the newly built corridor, requiring the completion of around 15,000 test kilometres across the provinces of Carinthia and Styria.
These trials aim to ensure that the new infrastructure is safe and reliable before it is handed over for daily use.
The testing programme includes high-speed runs, with sections of the line designed to accommodate speeds of up to 250 km/h.
Initial tests will be conducted using single locomotives and specially outfitted test vehicles fitted with sensors to measure a variety of factors, including track vibrations, power supply stability, and signalling performance.
Early stages will involve speeds up to 160 km/h, with speeds increasing as overhead line systems are assessed.
A key part of the trials involves verifying the European Train Control System (ETCS), which will be in use across the entire route. These ETCS tests will ensure compliance with EU-wide rail standards and will prepare the system for full integration into Austria’s wider network.
The test runs are being carried out by experienced train drivers who meet specific operational criteria, including prior experience with test train operations. In parallel, training sessions for future route drivers are underway. These include hands-on sessions, as well as the production of video materials to support remote learning and familiarisation.
While testing is underway, certain sections of the existing local rail network will be temporarily closed to allow safe access for test trains. Between 14 April and 12 June, 32 designated test days are planned. During these times, the S6 line in Styria (Werndorf – Hengsberg – Wettmannstätten) and the S3 line in Carinthia (Klagenfurt – St. Paul im Lavanttal) will experience service changes.
The Koralmbahn comprises 130 kilometres of new railway, including around 50 kilometres of tunnels and more than 100 bridges. It features 23 newly constructed or modernised stations.
The centrepiece of the route is the Koralm Tunnel, stretching approximately 33 kilometres beneath the Koralpe mountain range. Once operational, the line will reduce the journey time between Graz and Klagenfurt to around 45 minutes and form a key part of the Southern Line corridor, connecting Austria with wider trans-European networks.
