Vy operates on half-hour headways from Bergen to Arna, through the Ulriken Tunnel, the only way under the Ulriken mountain. There are a further 16 departures each way to Voss, of which six stop only at Arna and Dale before Voss, not allowing trips Bergen-Arna/Bergen-Dale, while ten stop at all stations, giving three services per direction an hour between Bergen and Arna. Three services continue from Voss to Myrdal.
Double track in the Ulriken Tunnel is currently under construction. This will allow NSB to increase headway to 15 minutes to Arna, and increase services on the Bergensbanen. The tunnel boring machine made the breakthrough in August 2017 with the new tunnel set to open in 2020.[2][needs update] The former tunnel will then go through renovation works with the opening date for the completed double track set to 2024.