Wikipedia
Wupper-Express
The Wupper-Express (RE 4) is a Regional-Express service in the German state of North Rhine-Westphalia (NRW) running from Aachen via Mönchengladbach, Düsseldorf, Wuppertal, Hagen to Dortmund. The service is operated every hour by DB Regio NRW. It is the third most widely used Regional-Express line in the area administered by the Verkehrsverbund Rhein-Ruhr with approximately 24,000 passengers a day.