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 N40) 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.
Use the N4/M4 as a template for routes that you add.
A Complete list is available at http://www.irishstatutebook.ie/2012/en/si/0053.html
Primary routes
N1/M1 Dublin City Centre to border north of Dundalk (continuing to Belfast as the A1)
N2/M2 Dublin City Centre to border north of Monaghan (continuing to Derry as A5)
N3/M3 Dublin City Centre to border north of Cavan (continuing to Eniskillen as various A roads) and reemerging into Ireland near Ballyshannon and continuing to Ballyshannon.
N4/M4 From Dublin City Centre to Sligo
N5 N4 Longford to Westport
N6 N4 Kinnegad to Galway
N7 Dublin to Limerick
M8/N8 N7 Portlaoise to Cork
N9 N7 Newbridge to Waterford
N10N9 Paulstown via Kilkenny to N9 Ballyhale
N11 Dublin to Wexford
N12 Monaghan to border (continuing on A3 to Belfast)
N13 N15 Stranorlar to Letterkenny (continuing on A2 to Derry)
N14 Letterkenny to N15 Lifford
N15 Sligo to N14 Lifford
N16 Sligo towards Eniskillen (continuing on A4)
N17 Galway to N4 Collooney
N18 N17 Claregalway to Limerick
N19 N18 Shannon to Shannon Airport
N20 Limerick to Cork
N21 Limerick to Tralee
N22 Cork to Tralee
N23 Castleisland to Farranfore
N24 Limerick to Waterford
N25 Cork via Waterford to Rosslare
N26 N5 Swinford to Ballina
N27 Cork to Cork Airport
N28 Cork to Ringaskiddy
N29 N25 Waterford to Belview port
N30 N25 New Ross to N11 Enniscorthy
N31 M50 to Dun Laoghaire
N32 M50 to Malahide Rd
N33 M1 to Ardee
N40 Cork South Ring Road
M50 Dublin ring road
Secondary Routes
N51 Drogheda – N52 Delvin
N52 N1 Dundalk to N7 east of Nenagh
N53 Dundalk to Castleblayney
N54 N2 Monaghan to N3 Cavan
N55 N3 outside Cavan via N4 Edgeworthstown to N6 Athlone
N56 N15 east of Donegal) to N14 Letterkenny
N58 Foxford (N26) to N5 near Swinford
N59 N4 Ballysadare via Ballina (N26), Westport (N5) to N6 Galway
N60 N5 Castlebar via Claremorris (N17) to Roscommon
N71 N40 Cork via Skibbereen, Bantry to N72 Killarney
N72 N25 Dungarvan via Fermoy (M8) to N70 Killorglin
N86 Tralee to Dingle
more to do