It connects the cities of Wuppertal, Solingen, Leverkusen, Cologne and Bonn and it is operated by National Express.

[4] Until December 2007, the service ran to Wuppertal-Oberbarmen, but was shortened due to a reduction in federal funding and operated only in the off-peak.

National Express also holds two spare sets of coaches and locomotives of class 182 (EuroSprinter) for the operation on the RB 48.

The ET 425 sets became available when Abellio Rail NRW won some tenders for operating services in North Rhine-Westphalia.

[4] In December 2002, the Rhein-Wupper-Bahn replaced the North Rhine-Westphalian section of the former Rhein-Wupper-Express (RE 6), which ran between Koblenz and Wuppertal.

In December 2003 it was shortened to terminate at Bonn-Mehlem because Rhineland-Palatinate would not provide sufficient funds for operations in its section.

One train runs late in the evening to Wuppertal-Oberbarmen, where it is parked overnight before returning early in the morning to Bonn.