M1 motorway the A5, the motorway takes a more northerly route through the East Midlands, via Leicester, Loughborough, Nottingham to Sheffield, where the M18 splits from the M1 at Junction 32 to head to Doncaster. Originally, the M1 was planned to end at Doncaster but it was decided to make what was going to be the "Leeds and Sheffield Spur" the primary route with the section to the A1(M) south of Doncaster given the separate motorway number M18. From Junction 32, the motorway passes Sheffield, Rotherham, Barnsley and Wakefield, reaching the original end of the motorway at (the original) Junction 44 to
M1 motorway Aberford. The new road involved the construction of a series of new junctions, bridges and viaducts to the east of Leeds. When the new section of M1 was completed and opened on 4 February 1999, the Leeds South Eastern Motorway section of the M1 was redesignated as the M621 and the junctions were given new numbers (M621 Junctions 4 to 7). The M1 was extended south from its original starting point at Junction 5 towards London in three stages. The first stage, opened in 1966, took the motorway south-east, parallel to the A41 to meet the A5 at junction 4