|Distance:||129.2 km (80.3 miles)|
|Meets:||R147, M50, R843 R121 R156, M3, N52, R163, R194, R178, R165, N55, R188, N54, R197, N87, A509, A46, N15|
|Former Number(s):||R230, L24, T10|
|Old route now:||R147, R936, R212|
| 1st border crossing: H336196|
2nd border crossing: G933589
|Route outline (key)|
Dublin – Aghalane
The N3 today starts at Junction 6 of the M50, the Blanchardstown Interchange. The road is D3 for over a kilometre, as far as the junction with the R843, from where it continues northwest as HQDC D2 for a further 3.5 km, bypassing Blanchardstown and Mulhuddart. It then becomes the M3 at Junction 4 (R156) south of Clonee.
51 km to the north-west, the motorway section ends at a roundabout with the N52 Kells bypass and the all-purpose N3 resumes. The route continues initially as a minimalist 2+2 dual carriageway for almost 10 km, via a roundabout with the R163, before stopping on another roundabout with the its old route (now the R147). Rejoining the old route (now R147 at the County Cavan border, it follows a predominately straight north-west course to Virginia.
As the road moves across the south Ulster countryside, with its characteristic drumlin topography, there are some bends, but none are dramatic. The road continues north-west, passing through Cavan countryside until we hit the next "urban" conurbation at Lavey. The road now travels through "deepest Ireland" – more hills than people. Eventually it turns right at a roundabout junction with the R212 (the original N3 passing through the town) and the N55.
The Cavan bypass is high-quality S2 with grade-separated junctions at its meetings with the R188 and the R212 (which skirts Butlersbridge), and there is a T-junction with the N54 to Monaghan. As the N3 continues north-west, the road bypasses Belturbet on a new section () opened in 2013 to replaces a poor-quality road. The newly opened section connects at Staghall Roundabout with the already improved section (1999) north of Belturbet. This links to the George Mitchell Bridge at Aghalane, which marks with border between Counties Cavan and Fermanagh and the route becomes the Northern Ireland A509.
Belleek – Ballyshannon
The Declaration of National Roads Order of 1994 reclassified the 7-km route between Cloghore (by Belleek) and Ballyshannon, previously a regional road, as a continuation of the N3 (reached from Aghalane via the A509, A4, and A46 in Northern Ireland).
The road itself is unremarkable, running through trees to the south of Assaroe Lake, formed on the River Erne by the Erne Hydroelectric scheme. It terminates at a grade-separated junction with the N15 in the townland of Ballyhanna south of the Ballyshannon bypass bridge.
Before implementation of the national roads scheme, the main road from Dublin to Cavan was numbered T35. Historically, the main route beyond Cavan then ran via the T10 and the Northern Ireland A34. However, the route of today's N3 northwest of Cavan is based on that of the former L24 in Counties Cavan and Donegal. This lower importance in the past was reflected in the narrow and twisting section of road near Belturbet, which has recently been replaced. See NRA press release 02/08/2013
At the Dublin end, the N3 used to start on the N2 in the city centre and proceed around the north side of Phoenix Park, the residence of the Irish President. The road bypassed Castleknock and approached the M50 as a dual carriageway. Since the recent "de-trunking" of national roads inside the M50, the N3 now starts at the Blanchardstown Interchange, and former sections of the N3 are now the R147.
Irish Statute Book
- Roads Act 2007 (Declaration of Motorways) Order 2009 - This instrument converts the following sections of the N3 to motorway: Littlepace to Loughsallagh, Loughsallagh to Pace