 The Ruhr area also contains the longest tram system in the world, with tram and Stadtbahn services from Witten to Krefeld as well as the Rhine-Ruhr S-Bahn network.Originally the system was even bigger, it was possible to travel from Unna to Bad Honnef without using railway or bus services.The Ruhr has one of the densest motorway networks in all of Europe, with dozens of Autobahns and similar Schnellstraßen (expressways) crossing the region.