To save resources and reduce CO2 emissions, alternative vehicle drive systems based on New Energy Carriers (NEC), i. e. different types of purely electric, hybrid, gas and bio fuels are increasingly used. These NEC change the risks in transport, especially in enclosed underground areas. Nevertheless, current guidelines do not cover the changing risks as only few scientific studies on the impact of NEC on safety issues are available. This gap is addressed by the German SUVEREN project, which investigates phenomena that may occur in connection with the use of NEC in underground urban traffic areas. The research project examines the impact of battery and gas fuels on the safety of enclosed car parks, delivery areas, bus depots and tunnels. The given paper provides insight in this project and its upcoming results leading to a safety concept for appropriate treatment of NEC in underground structures.