S1 (Rhine-Ruhr S-Bahn)

It runs from Dortmund via Bochum and Essen to Duisburg.

From there it travels south to Düsseldorf and Hilden before continuing to Solingen.

It is operated on weekdays at 15-minute intervals between Dortmund Hbf and Essen Hbf, at 20-minute intervals between Düsseldorf Hbf and Solingen and at 30-minute intervals between Düsseldorf and Essen, using coupled sets of class 422 four-car electrical multiple units.

Services were extended from Großenbaum to Düsseldorf on 22 May 1977 and from Bochum to Dortmund on 25 September 1983.

Services ran via Düsseldorf Airport Terminal station from 24 May 1998 to 28 May 2000.