The current Swiss Federal Railways mainline begins its climb from Erstfeld towards Göschenen and the north portal of the present Gotthard Tunnel. Here the line crosses the River Reuss next to Autoroute A2 between Amsteg and Intschi. This line uses several loops and switchbacks to gain elevation before reaching Göschenen. The Gotthard Base Tunnel will eliminate the need to send tonnage over this steep route but it is anticipated this track will remain in place as an alternate route.