The Rhein-Weser-Express (RE 6) is a Regional-Express service route in the German state of North Rhine-Westphalia, connecting the most important cities in Westphalia (among others Minden, Bielefeld and Hamm) with the Ruhr (especially Dortmund, Bochum, Essen, Duisburg, Düsseldorf, Neuss and Cologne). Cologne, Neuss, Düsseldorf and Duisburg lie on the Rhine and Minden lies on the Weser.

Until the timetable change in December 2016, this services was called the Westfalen-Express and ended in Düsseldorf Hauptbahnhof.

Until the timetable revision of 2002, the NRW-Express (RE 1) operated with five, and sometimes up to eight, double-deck carriages from Aachen to Bielefeld. In 2002 services were extended to Minden and at the same time the service was split into two routes. The Westfalen-Express was established, taking over the Hamm–Bielefeld–Minden section and extending to Düsseldorf. This change was intended in particular to improve the timeliness of the entire service.

A service called line RE 6a was put into operation as a pre-operation for the Rhein-Ruhr-Express on 13 December 2015. For the first time, Düsseldorf Hauptbahnhof was regularly connected with Cologne/Bonn Airport, serving on the way Neuss Hauptbahnhof, Dormagen, Cologne Hauptbahnhof, with some services also stopping in Köln Messe/Deutz in the peak.

...
Wikipedia