The Witten/Dortmund, Oberhausen/Duisburg railway is one of the most important railways in Germany. It is the main axis of long distance and regional rail transport on the east–west axis of the Ruhr and is served by Intercity-Express, InterCity, Regional-Express, Regionalbahn and S-Bahn trains.

The Rhine-Ruhr S-Bahn is a polycentric and electrically driven S-bahn network covering the Rhine-Ruhr Metropolitan Region in the German federated state of North Rhine-Westphalia. This includes most of the Ruhr, the Berg cities of Wuppertal and Solingen and parts of the Rhineland. The easternmost city within the S-Bahn Rhine-Ruhr network is Unna, the westernmost city served is Mönchengladbach.