Significant shares of regional passenger railway still rely on pollutive diesel vehicles. Alstom, Bombardier, Siemens, and Stadler have reacted and recently announced Battery Electric and Fuel Cell Electric Vehicles (BEVs and FCEVs). In this paper, we analyze to what extent these new vehicles can replace diesel technology on a large variety of regional railway lines in Bavaria, Germany. Our approach is based on two databases that we build: One for the announced emission-free vehicles and one for existing lines. We compare the lines and vehicles in terms of range, axle load, velocity, and specific power. The study reveals that 72 out of the 73 lines can be operated with an emission-free vehicle. The main driver for BEVs is their range and maximum velocity. Depending on these characteristics, they can operate between 53% and 82% of all lines. The main driver for FCEVs is their specific power and maximum velocity. One vehicle, the Alstom iLint, can only operate 18% of all lines due to its limited performance. The Siemens Mireo Plus H series has higher performance and can operate 97% of the lines. European Journal of Transport and Infrastructure Research, Vol 20 No 4 (2020)