Irish Roads

Road Classes
Primary Roads
Road Projects
Roads in Detail
The North
Items of Note



Details of the N3 national primary road.

Terminal Destinations:

Dublin -> Ballyshannon [1]


The N3 is 134.5 km long, and runs from Dublin city centre northwest to Cavan and on to the border with Northern Ireland. The route also connects from the Northern Ireland border at Belleek to Ballyshannon in County Donegal (the intermediate route through Northern Ireland follows the A509 to Enniskillen and A46 to Belleek). The N3, like many radial primary routes connecting Dublin to outlying parts of the island, commences as dual carriageway, with various route standards along later route sections, and poor two lane country route at the extreme in Donegal.

Route description:

The N3 commences at a junction with the N2 along Phibsborough Road, the N3 proceeding west from the junction along the North Circular Road and New Cabra Road. The Navan Road continues the route along the east side of the Phoenix Park. At a roundabout near the Castleknock Gate of the park, the Navan Road becomes dual two/three lane carriageway (previously had hard shoulders, now used as bus lanes) and follows a modern alignment to meet Junction 6 of the M50. The junction is a large perfectly circular roundabout junction, at grade for the N3 (M50 running underneath, with a railway line and canal crossing above it but below the roundabout).

The N3 meets another junction shortly after the M50 one, an at-grade roundabout providing access to/from Blanchardstown. From here the N3 proceeds along the Blanchardstown bypass, a dual two lane carriageway opened in 1991, passing east of the town of Blanchardstown and west of the town of Mulhuddart. Again, the hard shoulder has been replaced by bus lane along part of the route. There are grade separated interchanges providing access to the Blanchardstown Shopping Centre, as well as heavily settled population centres either side of the route. Further out, the dual carriageway continues along the Clonee Bypass, opened a year later in 1992. There are restricted grade separated interchanges at either end of the village (which is southwest of the N3), one also serving an industrial estate and extensive suburban estates (Pace).

From the end of the Clonee Bypass the N3 continues on a more northern direction as a simple two lane country road. This passes through Dunshaughlin and Tara, proceeding through the Tara-Skryne valley past the Hill of Tara. Further northwest the route enters Garlowcross and then Navan town, where the N3 meets the N51 (connecting east to Slane and west to Athboy). The town of Kells is situated further along the route, and the N52 (northeast to Ardee and southwest to Mullingar) crosses the N3 here. After Carnaross and Derver the N3 leaves County Meath and proceeds into County Cavan.

Lisduff is the next settlement along the N3, and the N3 passes along the east and north sides of Lough Ramor as it continues to the town of Virginia. Minor settlements lie along the route northwest from here to Cavan Town, including Lisgrea, New Inn, Lavey and Poles. Just outside Cavan Town the N3 veers north to proceed along the 9.5 km single carriageway Cavan Bypass, opened in 1999 at a cost of IR£20 million (~€25.4 million). The N55 to Athlone commences along this section of the N3, passing around the north of the town on a bypass opened in 2006.

The Cavan Bypass ends short of Butlersbridge, where the N54 from Monaghan joins the N3. Further north the N3 passes through Belturbet. West of the town the N87 (leading west and then north into Northern Ireland) begins, and the N3 veers north to the border. This last 3.2 km section of the N3 before the border was realigned as part of a cross-border project completed in 1999. The N3 crosses the border on the Senator George Mitchell Peace Bridge, with the road continuing to Enniskillen as the A509 (1.3 km of which was realigned).

Prior to the opening of this project, the N3 had terminated at the border since 1972, when the bridge at Aghalane was blown up during the Troubles. The bridge was not repaired for security reasons. It was in 1994 that the project to restore the cross-border link was initiated (along with the restoration of many other closed cross-border roads), as part of the peace efforts at the time. The project cost £9.6 million, with £6.6 million spent in the Republic, and £3 million spent in the north.

The final section of the N3 is located in County Donegal, running from the border with Northern Ireland near Belleek to Ballyshannon (continuing the route from Enniskillen via A46). This section of route was reclassified as the N3 in the early 1990s, it was previously the R230 (this route number was not used in the 1994 route classifications, and was appropriated for another route in Donegal in the 2006 classifications). The N3 in Donegal has not yet been upgraded. The predecessor to the N3, the T35, also had a route section in Donegal; along the R232 Pettigo-Laghey (which continues from the A35).

Upgrades under construction and planned:

The biggest upgrade planned for the N3 is the M3 motorway from Clonee to Kells. This will bypass Dunshaughlin, Tara, and Navan with 50 km of motorway/dual carriageway and will bypass Kells with 11 km of single carriageway. The project will be a PPP (public-private partnership) project involving private funding; as such, the route will be tolled. The project has an estimated cost, using 2000 figures, of €577 million including VAT and excluding the capital costs of tolling (estimated at €12.7 million inc. VAT). The preferred tenderer has been appointed, and the contract is due to be awarded by the NRA. Construction might begin in Spring 2007.

The M3 scheme has been the subject of much controversy (and court action), as it will pass by the Hill of Tara through the archaeologically rich Tara-Skryne valley. Archaeological investigations have been ongoing along the proposed route, and various plans are in place to mitigate against the intrusion caused by the construction of the motorway. Extensive information about the archaeology uncovered thus far along the route is available at the official project website, along with information about the route choice.

Another project is in planning for the N3 from the Cavan-Meath border (where the Clonee-Kells project will end) to north of Virginia. This project, including a Virginia Bypass, will be 11.4 km long, and the preferred route has been identified.

Beyond the end of the Cavan bypass, beginning at Butlersbridge, a further N3 realignment is planned. This project will proceed north for 9 km, including a Belturbet Bypass which will end west of Belturbet at the start of the realigned N3 to the border.

The only route section not already upgraded, or included in the above projects, is between Virginia and Cavan Town.


[1] Traffic Signs Manual, Chapter 2, Appendix 2, Table A2.2 - Terminal Destinations for National Routes : National Primary Routes, Dept. of Environment, 1994.


S.I. No. 187 of 2006 - Roads Act 1993 (Classification of National Roads) Order 2006 [PDF - 353 kB], Dept. of Transport website, accessed 25 Oct 2006.

National Route Lengths as of 31/12/2005 [PDF - 641 kB], NRA website, accessed 25 Oct 2006.

Major Road Schemes in Planning, NRA website, accessed 26 Oct 2006.

Explanatory Statement Accompanying the Draft Toll Scheme for the M3 Clonee to Kells Motorway [PDF - 65kB], NRA website, accessed 31 Oct 2006.

Completed Cavan By-pass Will Relieve Congestion and Improve Journey Times and Road Safety, Press Release, Dept. of Transport website, accessed 31 Oct 2006.

New £20m town bypass will divert 8,000 vehicles per day, Irish Independent, Tuesday 7 Sept 1999.

Historic re-opening of Belturbet border link, The Anglo-Celt, Thursday 1 April 1999.


M3 motorway website, accessed 31 Oct 2006.

M3 Clonee-Kells, NRA website, accessed 31 Oct 2006.

© Copyright 2006 Conal Watterson
(except where otherwise noted).

Last updated: 26 October 2006.