M18 motorway (Great Britain) and 12 June 2015. The M18 was originally to be part of the M1, but it was decided to route the M1 towards Leeds instead of Doncaster, and the routing of what would have been the M1 east of Sheffield became the M18. Data from driver location signs are used to provide distance and carriageway identifier information. The location sequence is a continuation of the M1 location sequence. !scope=col|miles !scope=col|km !scope=col abbr="Southbound"|Southbound exits (B carriageway) !scope=col|Junction !scope=col abbr="Northbound"|Northbound exits (A carriageway) !scope=col|Coordinates M18 motorway (Great Britain) The M18 is a motorway in Yorkshire, England. It runs from the east of
M621 motorway the 'M1 – A1 Lofthouse to Bramham' extension opened in 1999 adjustments were made to Junction 3 and the Leeds section of the M1 was re-designated as M621 (Junctions 3–7). M621 motorway The M621 is a short loop of motorway in England that takes traffic into central Leeds between the M1 and M62 motorways. The first section of the M621 to open, known at the time as the 'South West Urban Motorway', extends from the M62 to Junction 3 in central Leeds where it used to terminate at a roundabout which was also the terminus of the M1 motorway. This