Since winter 2016/2017, the public transport operator of the city of Karlsruhe (VBK) and the municipal utility company have been testing the energy-efficient heating of turnouts with district heat instead of electricity. For the trial operation with the new Turnout Sandwich Radiator (Fig. 1), four grooved rail turnouts at the Rheinhafen tram station were selected because at that location, the district heat infrastructure was already in place. This pilot project is the first to put the lifecycle cost focus on the energy consumption of turnouts. And with good reason: depending on the kind of heat pump, the energy saving potential exceeds than 90 percent. Already two years ago, Vossloh started with the implementation of this concept as heightened environmental awareness and more stringent energy-efficiency laws and requirements had resulted in a general rethink. Urban transport systems stand for eco-friendly mobility so municipal operators aspire to be pioneers in sustainability also as regards their infrastructure – especially when the technical prerequisites for the use of renewable energies have already been established.