Bundesautobahn 42 (translates from German as Federal Motorway 42, short form Autobahn 42, abbreviated as BAB 42 or A 42) is an autobahn in western Germany. It connects Kamp-Lintfort with Castrop-Rauxel, linking several large cities in the Ruhr area, such as Dortmund, Duisburg, the North of Essen and Gelsenkirchen. It is colloquially known as Emscherschnellweg, after the river Emscher, which it roughly follows. Construction went underway in the 1970s and 1980s.
