Details of the N4 national primary road.

Terminal Destinations:

Dublin -> Sligo [1]

Route:

The N4 is 207.3 km long (the longest national primary road in the State), and runs from Dublin city centre northwest through the upper Midlands to Sligo. The N4 also serves as an arterial route for traffic between Dublin and Galway; the N6 route to Galway diverges from the N4. County Mayo is also served by the N4, as the N5 route to Westport connects from the N4 at Longford (the N26 route to Ballina in Mayo connects from the N5). The N4 leaves Dublin as a dual carriageway, three lanes either side along part of it, and is two lane motorway from the outskirts of Dublin to Kinnegad (this section is the M4 motorway). Dual carriageway brings the route past Mullingar, and the route proceeds as single carriageway to County Sligo. The section of N4 leading to Sligo town is dual carriageway, and the route passes through the centre of Sligo town as a mostly dual carriageway inner relief road.

Route description:

The N4 commences at O'Connell Bridge (junction with N1) and proceeds up and down the quays along both sides of the River Liffey. In the outward direction the N4 runs via Aston's Quay, Crampton Quay, Wellington Quay, Essex Quay, Wood Quay, Merchant's Quay, Usher's Quay, Usher's Island and Victoria Quay (in the inward direction via Frank Sherwin Bridge, Wolfe Tone Quay, Sarsfield Quay, Ellis Quay, Arran Quay, Inns Quay, Ormond Quay Upper, Ormond Quay Lower and Bachelor's Walk). At the top of the quays the route passes in front of Heuston Station at Kingsbridge, and down the side of the station via Saint John's Road West. Alongside the station the route becomes urban dual carriageway.

West of the railway station the route meets the South Circular Road at grade at a busy junction above the railway line. The dual carriageway continues west along Con Colbert Road and the Chapelizod Bypass (opened in 1987). This section of the N3 is dual two lane carriageway, with an additional lane in each direction for buses having replaced the hard shoulders. The Chapelizod Bypass winds along the south side of the Liffey Valley, continuing on to the earlier Palmerstown Bypass (or Palmerstown-Ballydowd). The Palmerstown Bypass was possibly open in the early 1980s, and was completed sometime around 1985. It has at least two at-grade junctions with median breaks along it.

At the end of the Palmerstown section of the road, the N4 meets junction 7 of the M50 Dublin ring road, at a roundabout intersection (the junction is at-grade with the N4; the M50 passes below). Junction numbering along the N4 begins at this intersection (as Junction 1 on the N4), according to a scheme introduced by the NRA in 2006. The Liffey Valley Shopping Centre is located just southwest of this busy junction, accessed by Junction 2. Around Lucan the N4 continues as a dual two lane carriageway (three lanes each way for a short distance from the M50 junction), again with an additional lane in each direction for buses provided by supplanting the previously present hard shoulders. The Lucan Bypass was opened in 1988 [2], and is 8 km long including the section from the M50. Junctions 3 and 4 of the N4 are located east and west respectively of Lucan village (bypassed to the south).

West of Lucan, the N4 route proceeds as the M4 motorway (dual two lane carriageway with hard shoulder). The first section of the M4, bypassing Leixlip, Maynooth and Kilcock, opened in 1994. The project, comprising 17.6 km of motorway, cost IR£63 million (~€80 million), and included the construction of 11 bridges; one of them being a major crossing of the River Liffey. Junction 5 (according to the route numbering introduced by the NRA in 2006) of the N4, east of Leixlip in County Kildare, marks the beginning of the M4. Full access is provided at Junction 6 west of Leixlip also. Maynooth is served by Junction 7, south of the town. This initial section of the M4 reaches Junction 8, directly west of Kilcock.

The M4 now proceeds west along the border between Counties Kildare and Meath (mostly in the former county) along a bypass project opened in December 2005. The Kilcock-Kinnegad project was a PPP (Public-Private Partnership) scheme, and the route is tolled and operated by Eurolink. A toll plaza is located west of Junction 8, and Junction 9 (for Enfield) has tolls on the eastbound off slip, and westbound on slip. Junction 9 connects to the Enfield relief road, a 2.6 km single carriageway bypass of the town opened in 2002 as part of the N4 at the time. Junction 10, 11 (this is also Junction 1 on N6) and 12 mark the end of the Kilcock-Kinnegad scheme, and are restricted junctions providing access to/from the N6, rest of N4, and Kinnegad.

The N4 continues west as dual carriageway, leaving County Meath and entering County Westmeath. The 4.5 km section from Junction 12 (end of M4 west of Kinnegad) to McNead's Bridge was opened in July 2005, connecting at the eastern end to a previously existing section of dual carriageway. 5.3 km of dual carriageway opened in 2001 brings the N4 towards Mullingar. Mullingar is bypassed to the east by a dual carriageway opened in 1994, which is about 8km long. The N4 continues northwest from the Mullingar Bypass along a 6km alignment, upgraded to wide two lane carriageway in 2001, as far as Ballinalack through which the N4 passes. The N4 also passes through Rathowen, and to the border with County Longford along a 4km single carriageway alignment upgraded in 2001.

In Longford the N4 continues to Edgeworthstown, which has a 3 km single carriageway "inner relief road", opened in June 2006, skirting the south of the town. The route passes west towards Longford, and bypasses the town to the northeast along a route opened in the mid-1990s. Proceeding northwest to Carrick-on-Shannon the N4 passes through Newtown Forbes, passes east of Roosky, then passes through Dromod, Aghamore and Drumsna. At Carrick-on-Shannon the N4 crosses the town and the River Shannon east-west.

West of Carrick-on-Shannon the single carriageway N4 has been upgraded in three stages to Boyle. The first section is between Corotober and Meera, finished around 2001/2002. From Meera there is a 3.3 km section of realigned single carriageway to Hughstown, opened in May 2004. The section between Hughstown and Rockingham was upgraded around the same time as "Meera/Corotober". The entire scheme between Cortober and Rockingham, consisting of 8.7km of upgraded N4 road and 2.1 km of new N4 road, was officially opened in May 2004, having cost €27 million.

The Curlews Bypass continues the N4 around the east side of Boyle and on northwards into County Sligo. Officially opened on 12 April 1999, the 16.5 km long section of new single carriageway was built between 1995 and 1998, skirting the Curlew Mountains and passing west of Lough Key and Lough Arrow. The project cost IR£27 million (~€34.3 million), and was managed by Roscommon County Council (the road passes from Roscommon into County Sligo). The N4 had previously run through the Curlew Mountains directly, with a steep ascent and descent.

For 12 km from Castlebaldwin to Cloonmahon (south of Collooney) the N4 is narrow two lane country road (not upgraded). Upgraded single carriageway road recommences north of Cloonmahon. Further north, where the N17 meets the N4, the route becomes dual carriageway, proceeding along the Collooney Bypass. This 10 km dual carriageway section between the N4/N17 junction at Collooney and Carraroe in the suburbs of Sligo cost €17 million and was completed by 1998.

The final section of the N4, into Sligo, has now been upgraded. The Sligo Inner Relief Road, including 4.6 km of dual carriageway and 1 km of single carriageway, was opened in September 2005 after a year and a half's construction. The dual carriageway passes through the town centre, ending across Hughes Bridge as four lane single carriageway; where the road out north of Sligo continues as the N15.

Upgrades under construction and planned:

The most major project planned/under construction on the N4 is a new route section between Longford and Drumsna (west of Carrick-on-Shannon). This will involve approx 20 km of route, split across three projects; Dromod/Roosky, Newtownforbes Bypass, Roosky/Newtownforbes. The Dromod/Roosky section, 10 km of 2+1 road, is under construction as of 2006, and will bypass the towns of Rooskey and Dromod from south of Rooskey to Drumsna. The other project sections are planned as wide two lane road.

A 6 km standard two lane bypass of Carrick-on-Shannon is also in planning. The preferred route for this project has been identified.

There are also plans to upgrade the remaining low quality N4 road in County Sligo; 12 km of route between Castlebaldwin and Cloonmahon.

Footnotes:

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

[2] The Irish Emigrant, Issue No. 93, 13 Nov 1988, Emigrant Online, accessed 19 Nov 2006.

References:

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.

Dáil Éireann, Vol 594, 7 Dec 2004, Written Answers: Road Network, Parliamentary Debates, Oireachtas Historical Debates website, accessed 19 Nov 2006.

Dáil Éireann, Vol 532, 6 Mar 2001, Written Answers: Roads Funding, Parliamentary Debates, Oireachtas Historical Debates website, accessed 19 Nov 2006.

National Road Schemes Completed in 2005, NRA website, accessed 19 Nov 2006.

National Road Schemes Completed in 2002, NRA website, accessed 19 Nov 2006.

National Road Schemes Completed in 2001, NRA website, accessed 19 Nov 2006.

Work Starts on Second Mullingar Bypass, Press Release, 18 Oct 2004, NRA website, accessed 19 Nov 2006.

Status of Road Projects at the End of 2002, NRA website, accessed 19 Nov 2006.

Major Road Schemes in Planning, NRA website, accessed 19 Nov 2006.

Economic and Social Infrastructure Operational Programme: Progress report on Programme Implementation - First Half 2001 [Microsoft Word Document - 539 kB], Dept. of Transport website, accessed 23 Nov 2006.

Two New Roads Opened as Infrastructure Investment in BMW Region Increases By 62%, Press Release, Dept. of Transport website, accessed 23 Nov 2006.

Roads Projects (Official Opening Of The Curlew Mountains Road Project), Roscommon County Council website, accessed 23 Nov 2006.

N4 Sligo Collooney Road, Atkins plc. website, accessed 23 Nov 2006.

National Road Schemes Under Construction in 2006, NRA website, accessed 23 Nov 2006.

Resources:

N4 Kilcock - Kinnegad, NRA website, accessed 19 Nov 2006.

Map of N4 Kilcock - Kinnegad [PDF - 355 kB], NRA website, accessed 19 Nov 2006.

Opening brochure for N4 Kilcock - Kinnegad [PDF - 3.22 MB], NRA website, accessed 19 Nov 2006.

Tolling Information Brochure for N4 Kilcock - Kinnegad [PDF - 529 kB], NRA website, accessed 19 Nov 2006.

M4 Kinnegad-Enfield-Kilcock Motorway Toll Road List of Maximum Tolls Payable in Year Ending 31st December, 2006 [PDF - 60 kB], NRA website, accessed 19 Nov 2006.

Eurolink Motorway Operations website, accessed 19 Nov 2006.

Roads to the West, The Institute of Engineers of Ireland, accessed 23 Nov 2006.