 The Thun–Steffisburg tram line closed in 1958, and since then the STI network has been covered exclusively by buses.Trolleybuses, powered by electricity drawn from overhead wires, were used on the main line, Thun–Beatenbucht, connecting at Beatenbucht with the Thunersee–Beatenberg funicular and with a motorbus route covering the section to Interlaken.In 1982, the trolleybuses were replaced with conventional, diesel-powered buses.