 If it is built as per the original plans, Phase II of the tunnel will bring its length to about 20 km, and will link Zurich with Zug.Even following its completion, it is planned to retain the intermediate exit to Thalwil, which would still be used by passenger and freight trains going to Chur as well as by international trains to Austria.Until Phase II is completed, capacity and speeds both remain heavily constrained by traditional routes; the Swiss Federal Railways has reportedly included the work in its long term expansion plan for 2030-2035.