The N2 commences at junction 5 of the M50 motorway. It then runs as a dual-carriageway for 17 km (10.5 miles) from the M50 to north of Ashbourne, County Meath. This project was opened on 25 May 2006, and includes 3.5 km (2.2 miles) of three lane dual carriageway built to motorway standard. The route is the first to have a 120 km/h (75 mph) special speed limit (this was previously reserved for motorways, see Road speed limits in the Republic of Ireland for particulars). 13 km (8.1 miles) of this dual carriageway stretch became motorway on 28 August 2009. (see M2 motorway).

The route continues through Balrath towards Slane, where a dangerous bridge brings the road through the town by the historic Hill of Slane, now home to the occasional rock festival. The N2 continues through Collon in County Louth. Just after Ardee, the N2 meets the N33, coming from the nearby M1 motorway, which most traffic coming from Dublin uses for N2 destinations north of Ardee. In County Monaghan, the N2 bypasses Carrickmacross to the east, along a bypass opened on 31 January 2005. This 9 km wide single carriageway has been named The Kavanagh Way, after Monaghan writer and poet Patrick Kavanagh. The route by-passes Castleblayney and Clontibret on the way to Monaghan. North of Monaghan town, the N12 diverges east to the border. The N2 continues north through Emyvale to reach the border at Moy Bridge directly south of Aughnacloy, County Tyrone. From here, the road becomes the A5 road to Omagh, Letterkenny and Derry.

Projects completed on the N2 include a 16 km (10 miles) 2+1 bypass of Castleblayney, which opened on 5 November 2007 .^[1] A 3 km (1.9 miles) single carriageway bypass of Monaghan town to the east was opened on 25 September 2006 by Pat Gallagher, Junior Minister For Transport.

Previous planned projects along the N2 included a 4 km (2.5 miles) bypass of Ardee and a 6 km (3.7 miles) bypass of Slane. These projects have now been incorporated into a single project which extends from the end of the Ashbourne Bypass to north of Ardee (N2 Ashbourne to Ardee).^[2] The feasibility report for this scheme recommends a dual carriageway cross section. That section of the N2 from the end of the Castleblayney Bypass to the NI Border at Aughnacloy is also being studied (N2 Clontibret to NI Border).

Because the N2 contains narrow and steep-gradient sections in the environs of Slane, Collon and south of Ardee, Transport Infrastructure Ireland (TII) recommends that hauliers heading from Dublin to Derry should instead use the M1 motorway from Dublin as far as its junction with the N33 road, then follow N33 to its junction with N2, north of Ardee.

There have been calls (by political parties in both the Republic of Ireland and Northern Ireland) to upgrade the whole Dublin-Derry route to dual carriageway. This would entail upgrading both the N2 and also the A5 in Northern Ireland.

A 2007 Fianna Fáil election policy document on transport included a plan for a dual carriageway from Dublin to Letterkenny and Derry as one of Fianna Fáil's promises if re-elected. Although the N2 was not included in Transport 21, and the Monaghan and Carrickmacross by-passes are single lane national primary roads, a feasibility report completed on the N2 Ashbourne to Ardee section recommended a dual carriageway cross section (including the Slane By-pass).^{[citation needed]} Also, in order to tie in with the A5 Western Transport Corridor north of the border, work on the feasibility study for the N2 Clontibret to NI Border Scheme was commenced ^{[citation needed][when?]}. As of 2024, this route has a defined corridor, and is progressing to the design phase. An upgrade of the section from Ardee to Castleblaney to dual carriageway has reached final design, but is suspended due to lack of funding.

In October 2006, the Irish government announced it was funding infrastructure to the value of €1 billion within Northern Ireland where such projects improved connectivity between parts of the Repbublic. One of the proposed projects to be funded was the upgrading of the A5 Derry–Omagh–Aughnacloy road to dual carriageway for a distance of 88 km (55 mi).^[3] The Irish Department of Finance website confirmed on 22 March 2007 that £400 million had been set aside for Northern investment to include a dual carriageway to Derry and Donegal, although the A5 project itself was beset by delays and as of 2024 has still not commenced.

On 30 September 2008, it was announced that a 13 km (8.1 miles) section of the current N2 from Killshane to Ashbourne was under consideration for re-designation to motorway standard. Public consultation finished in December 2008.^[4]

On 14 July 2009, it was announced that the 13 km (8.1 miles) stretch had received ministerial approval to be re-designated.^[5] It became a motorway on 28 August 2009.

• Roads in Ireland
• Motorways in Ireland
• National secondary road
• Regional road

• Roads Act 1993 (Classification of National Roads) Order 2006 – Department of Transport
• Official site of the N2 Ashbourne Bypass/M50 Junction project
• National Roads Authority (details of projects completed, under construction, and planned on the N2, and other routes)