The M1 is a major motorway in England connecting London to the city of Leeds in northern England, but also linking several important towns and cities along the way, including Milton Keynes, Northampton, Leicester, Nottingham, Mansfield and Sheffield. It also links to the M6 and M45 motorways near Rugby, the M25 near Potter's Bar, the M69 at Leicester, the M62 near Leeds.
There is also an M1 motorway in Northern Ireland. It runs from Belfast to Dungannon, bypassing Lisburn, Lurgan, Craigavon and Portadown on the way.
The M1 motorway in the Republic of Ireland consists of several short sections built as bypasses of sections of the N1 road, running from Dublin toward Belfast.