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 (Republic of Ireland) and 9.4 km south of the border. This allows traffic to flow freely from Dublin Port on motorway/dual-carriageway standard road to the Hillsborough Roundabout, located south of Lisburn. This is Transport Infrastructure Ireland's Exit numbering scheme for the M1. all junctions feature their number on road signs. The upgrade of the N1 is now complete in the Republic of Ireland, the first major route to be completely upgraded to motorway/dual carriageway standard (outside of Dublin city centre) as per the National Development Plan. The Northern Irish authorities have no plans to replace the A1 route (currently dual carriageway) with motorway,