Running north west from Luton, the road travels through Bedford, Kettering, Market Harborough, Leicester, Loughborough, Derby and Matlock before going through the Peak District to Bakewell, Buxton, Stockport, Manchester, Chorley, Preston, Lancaster, Kendal and Penrith before arriving in Carlisle.
South of Nottingham, the road is paralleled by the M1 motorway, and north of Manchester the M6 motorway approximates its course.