This is not true. It depends on the city. Geneva and Lausanne are building without loops, as well as Lugano. Otherwise, Bern extension will have a loop, like Basel, Zurich, Glattalbahn. Bern ordered trams with one cab at each end to be more flexible during construction work and to replace the old RBS trams on line 6. But, they will receive Tramlinks with just one cab very soon. Limattalbahn is a specific case. It will extend to Baden and is a suburban dual voltage tram.