Originally, one had to travel by train to Bo and then change to the bus. The NSB has been very protective of its passenger rail service and wished to avoid competition, but the extension to Oslo was granted. This route, called the Haukeliekspressen, travels over the high Haukelifjell plateau. The plateau is snow covered most of the year, and in winter the snow is very heavy. However, the service is operated year-around.
Several tunnels are on the route.
Although the Oslo-Haugesund route is the main section, connections are now possible to and from Bergen, Voss, Stavanger, and Kristensand. The Voss-Kristensand section called Setesdalsekspressen travels through the beautiful Setesdal Valley, over the Haukelifjell plateau and into Voss, which passes near several spectacular waterfalls. The Stavanger-Oslo route, called the Suleskaredspressen, is fairly new and traverses very high mountainous areas. The highway is closed in the winter and this service does not begin until June. Even in June the highway is carved through snow that stands higher than the bus.