The M40 corridor is a term used to describe the area adjacent to the M40 motorway, running through England. It is one of the main routes between London and Birmingham, the other being that followed by the M1 motorway. The term also applies to rail, as the Chiltern Main Line also runs in the same area between the two cities. The route taken by the railway line closely follows the motorway except for the central section where the railway does not serve Oxford. Unlike the motorway, the Chiltern Main Line stretches deep into both cities.