|Location Map ( geo)|
|To:||Carrickcarnan (border) (J071171)|
|Distance:||89.9 km (55.9 miles)|
|Meets:||M1, N52, R132, R173, R174, A1|
|Route outline (key)|
As with all national roads in the Republic of Ireland, sections of the route may be classified as motorway, and in such cases the national road number is retained, but the prefix letter is changed from N to M to indicate this status. Thus while almost all of the N1 is today classified as motorway (and is therefore signed as M1), the M1 remains, legally and administratively, a part of the overall N1.
The N1 originally began in the very heart of Dublin, at the northern end of O'Connell Bridge over the Liffey, but since 2012 its starting point has been moved north to the Turnapin Interchange (J1 of the M1 / J3 of the M50), and from here the road is classed as a motorway all the way to Junction 18 (Carlingford). Only the final nine kilometres from there to Carrickcarnan and the border between Counties Louth and Armagh retain non-motorway status and are therefore still signed "N1"). Most of the remainder of the original, pre-motorway, route of the N1 through Drogheda and Dundalk has been reclassified as of regional status, principally as the R132.
Over time there have been various attempts to create a new route north out of Dublin. One of the most promising was put forward in 1971, and suggested a motorway running north from Croke Park (at Croke Park it would have merged with another motorway running to Grand Canal Dock and beyond). Although there is only limited information available on this, it's logical to assume that, had this been built, it would have become part of the N1/M1. Instead, the closest any motorway ever got was the Santry Bypass.