Wikipedia
Rhein-Erft-Express
The Rhein-Erft-Express is a Regional-Express service in the German states of North Rhine-Westphalia and Rhineland-Palatinate. It is numbered as line RE 8 and connects the cities of Mönchengladbach, Cologne, Bonn and Koblenz Hauptbahnhof with each other and their surroundings, running hourly. From Monday to Friday it is complemented by a Regionalbahn stopping service, the Rhein-Erft-Bahn (RB 27), running between Rommerskirchen (in the rush hour Mönchengladbach Hauptbahnhof) and Koblenz Hauptbahnhof. On weekends it stops at some additional stations between Cologne Hbf and Koblenz Hbf.