This will be one of the last times the old GT8-100C/2S TramTrains are used. They can be driven from both ends, and such are used for shuttle services like this, where normal turning loops are not available. Starting next year, the remaining C/2S services will instead be served by the new class 492 TramTrains.
In Karlsruhe, the trams are actually technically double-ended. They can be fully operated from the rear and driven at full speed. But since there is no rear-view mirror there, you cannot carry passengers, and only one side has doors. But every morning, a train reverses from Ettlingen to Marxzell to pick up a load of students right on time for school. The next loop is all the way up the mountain at Bad Herrenalb, and we don't have time for that…