Die A40 Autobahn in Essen, Nordrhein-Westfalen, Northwestern Germany. Bundesautobahn 40 is one of the busiest Autobahnen in Germany. It crosses the Dutch-German border onto the Dutch A67. It also crosses the Rhein river, and leads through the Ruhr river valley toward Bochum, becoming B1 at Dortmund and mergeing into the A44 near Holzwickede. It has officially been named Ruhrschnellweg (Ruhr Fast Way), but locals call it Ruhrschleichweg (Ruhr Crawling Way) or “the Ruhr area’s longest parking lot” due to actual traffic. According to Der Spiegel, it is the most congested motorway in Germany.