S1 (Rhine-Ruhr S-Bahn) Services ran via Düsseldorf Airport Terminal station from 24 May 1998 to 28 May 2000. Services were extended from Düsseldorf to Solingen on 13 December 2009, replacing part of the former line S 7 service. S1 (Rhine-Ruhr S-Bahn) Line S1 is a S-Bahn line on the Rhine-Ruhr network. It is operated by DB Regio. It runs from Dortmund west over Essen to Duisburg. From there it travels south to Düsseldorf and Hilden before continuing to Solingen. It is operated at 20 minute intervals, using coupled sets of class 422 four-car electrical multiple units. Line S 1 runs over lines built
Ruhr system valid for the entire area. The Ruhr region is well-integrated into the national rail system, the Deutsche Bahn, for both passenger and goods services, each city in the region has at least one or more train stations. The bigger central stations have hourly direct connections to the bigger European cities as Amsterdam, Brussels, Paris, Vienna or Zürich. The Ruhr area also contains the longest tram system in the world, with tram and Stadtbahn services from Witten to Krefeld. Originally the system was even bigger, it was possible to travel from Unna to Bad Honnef without using railway or bus