National Routes in Ireland are numbered Nxx except for those sections that are motorways where the N is replaced with an M
These are divided into National Primary routes (N1 to N31) and National Secondary routes (N51 to N87). There are approximately 2,750 km of Primary Routes and 2,700 km of Secondary Routes.
It is planned to include information here on all these routes and the level to which they are mapped.
N1/M1 From Dublin City Centre to border north of Dundalk (continuing to Belfast as the A1)
N2/M2 From Dublin City Centre to border north of Monaghan (continuing to Derry as A5)
N3/M3 From Dublin City Centre to border north of Cavan (continuing to Eniskillen as as various A roads) and reemerging into Ireland near Ballyshannon and continuing to Ballyshannon.
N4/M4 From Dublin City Centre to Sligo
N5 From N4 Longford to Westport
N6 From N4 Kinnegad to Galway
N7 From Dublin to Limerick
N8 From N7 Portlaoise to Cork
N9 From N7 Newbridge to Waterford
N10From N9 Paulstown via Kilkenny to N9 Ballyhale
N11 From Dublin to Wexford
N12 From Monaghan to border (continuing on A3 to Belfast)
N13 From N15 Stranorlar to Letterkenny (continuing on A2 to Derry)
N14 From Letterkenny to N15 Lifford
N15 From Sligo to N14 Lifford
N16 from Sligo towards Eniskillen (continuing on A4)
N17 From Galway to N4 Collooney
N18 From N17 Claregalway to Limerick
N19 From N18 Shannon to Shannon Airport
N20 From Limerick to Cork
N21 From Limerick to Tralee
N22 From Cork to N21 Farranfore
N23 From N21 Castleisland to N21/N22 Farranfore
N24 From Limerick to Waterford
N25 From Cork via Waterford to Rosslare
N26 From N5 Swinford to Ballina
N27 From Cork to Cork Airport
N28 From Cork to Ringaskiddy
N29 from N25 Waterford to Belview port
N30 From N25 New Ross to N11 Enniscorthy
N31 From M50 to Dun Laoghaire
N32 From M50 to Malahide Rd
N33 From M1 to Ardee
M50 Dublin ring road