In the French Occupation Zone, the railways were grouped into the Operating Association of the Southwest German Railways () with its headquarters in Speyer. The Operating Association included the railway divisions of Karlsruhe (in the US Zone), Mainz and Saarbrücken. After the Saarland was transferred from the French Zone and was given its own state railway – the Railways of the Saarland () – the rest of the network of the Saarbrücken division went into the new Trier division. After the Deutsche Bundesbahn was formed this Operating Association was merged with it.