The M1 motorway is a motorway in Republic of Ireland. It forms the large majority of the N1 national primary road connecting Dublin towards Belfast along the east of Ireland. The route heads north via Drogheda and Dundalk to theNorthern Irish border just south of Newry in County Armagh, where it becomes the A1 and further on, the M1. In all, the road connects Dublin with the three largest towns in the Republic of Ireland, excluding the major cities, Drogheda, Dundalk and Swords. It also forms a significant part of the road connection between Dublin and the Northern Irish cities of Newry, and Lisburn. The route is part of European route E01.