Berlin (dpa) - According to its own calculations, Deutsche Bahn will invest around twelve billion euros in new trains by 2026. The largest item is the new ICE4 trains, whose fleet is expected to grow from 39 to 137. In addition, there are double-decker intercity trains, Eurocity trains, regional trains and S-Bahn trains, the board said. The new trains are expected to significantly increase the number of passengers. The railway wants to have long-distance trains running between the big cities every 30 minutes. In the end, it means that long-distance traffic is to be expanded to a metropolitan S-Bahn, it says.