National Primary Route 8

Status : Complete

M8 Motorway Logo


Opened : 1992 - 2010

Motorway : 158.5 km
City Streets : 5.4 km

The N8 (formerly T6) runs from the large midlands town of Portlaoise down to Cork, Ireland's second largest city. It used to originate in the centre of the town, but from 1997-2010 it started at junction 17 of the M7 south of the town. The old route ran directly south, first stopping off in the cute town of Abbeyleix, followed by Durrow, which has a famous eponymous book - an illustrated monastic manuscript dating from the middle ages. A little further is the tiny village of Cullahill.

In May 2010, the N8's starting point was moved once again when a new Y-shaped motorway opened. This motorway extended the M7 further south as far as Borris-in-Ossory and also marked the completion of the M8 Dublin-Cork motorway. The M8 splits off from the M7 where it crosses the rural road R430. The nearest town to this is the tiny village of Aghaboe. From here the M8 winds south until it reaches the old N8 south of Cullahill. After this, the old and new routes parallel each other closely.

Passing Urlingford, the route reaches a triangle formed by the southwesterly old N8, the northwesterly N62 and the westerly N75, allowing access to the large town of Thurles from north and southbound traffic. From here the route continues south past the oddly named Horse and Jockey. This whole section was bypassed by the M8 motorway in December 2008, which closely followed the original alignment.

The next stop on the journey is Cashel, famous for the huge rock with a windswept church perched precariously on the summit. The old route passed through the town but the new bypasses to the east in a wide arc and was opened in October 2004 as dual carriageway. The bypass is hilly and windy, however, and its conversion to motorway in September 2008 was not accompanied by an increase in the 100 km/h limit.

South of here, the route runs down to Cahir (bypassed in October 2007) before passing in a straight line between mountains. The full scheme to replace this section opened in July 2008, and very closely parallels the original route. This section went blue along with the rest of the 2008 redesignations.

The old route next passes through the famous-for-its-cheese Mitchelstown, where the N73 route is spawned and heads west to Mallow. The main route veers south for the final run to Cork. In July 2006 a temporary single carriageway bypass was opened running around the town to the west. Until May 2009, this served as both an N73 and N8 bypass, but since then the whole area has been bypassed again by a new section of M8. The single carriageway is now exclusively for the use of N73 traffic.

Entering Cork's commuter road network, a tolled motorway bypass of Fermoy opened in October 2006. In a straight line south of here, the road passes the wet-sounding Watergrasshill, bypassed in September 2003, before taking a very windy easterly route around the suburb of Glanmire. Glanmire's bypass opened in 1992 and moved the entry point of the N8 from the area of Lota south of Glanmire east to a new large (but poor-standard) roundabout junction of the N8 and N25, known as Dunkettle. The dual carriageway took an incredible 7 years to build due to the country's dire financial situation at the time. The old N8 was renamed R639. In addition the bypass was so windy that the motorway redesignations of August 2009 required a reduced 100 km/h limit in order to safeguard traffic.

A tunnel, the Jack Lee Tunnel, extended the route (originally as N25 but N40 as of 2012) under the River Lee and around the south of Cork in 1999, and the west-to-east movement across the Dunkettle N8/N25 junction was grade-separated with a flyover. This still is woefully inadequate, however, as there are many major traffic flows through this junction - not just east-west. A major upgrade of Dunkettle junction to full or mainly freeflow is therefore planned for the future. A dedicated site exists.

Update 12/07/2019: The Dunkettle Interchange has enabling works underway, but the projected cost of the project has ballooned, and may now have to be re-examined by the Government. There have been some other cost overruns on capital projects recently and they are anxious that this one does not share the same fate.

Update 06/10/2020: The full Dunkettle Interchange was retendered and is due to start by the end of the year. It will take several years to build.

Update 20/01/2021: Dunkettle Interchange construction got fully underway in December. It is expected to open in stages until autumn 2023.

Update 27/03/2022: The most recent drone video of the Dunkettle Interchange project shows the progress made so far in a timelapse.

Update 18/09/2022: Here is the latest video drone update on the Dunkettle scheme. The first half focuses on the local road network coming together to the northeast of the interchange, and the new flyover at Little Island. Later on in the video the southern half of the area is covered. The very end shows the place where there is currently an offslip from the roundabout into an industrial area right in front of the tunnel entrance. From the layout of the new roads, it looks like this will be removed soon.

Update 07/01/2024: A video of the Dunkettle Interchange in Cork documents the work done on the final major element to open to traffic - the N25 East to M8 North ramp. This long ramp which has to combine with the ramp coming from the new Little Island interchange has made a lot of progress recently and should be ready for use within a month or two. The entire scheme was due to open by April of this year and still seems to be on track.

Update 12/02/2024: Today the Dunkettle Interchange has completely opened to traffic. It has taken 4 years to build. It looks great from the air! From the article:

The Dunkettle Interchange is the junction of four national roads, the M8 Cork-Dublin Motorway; the N25 Cork-Waterford/Rosslare route; the N40 Cork South Ring Road and the N8 Dunkettle-Cork city national route.
The interchange is located five kilometres east of Cork City centre and lies mainly within the Cork City Council administrative area.
The project has delivered eighteen new road links totalling 10km in length and seven new bridge structures, as well as upgrade works carried out on five pre-existing structures; and upgrades and resurfacing works to the N25 road between Tivoli Roundabout and the Little Island Interchange.
Traffic volumes through the Dunkettle interchange are at an all-time high, approaching 120,000 vehicles on the busier days of the week.
Despite this, Transport Infrastructure Ireland reports that journey times during peak hours have reduced by almost 50 per cent on average as a result of this upgrade project.
Journey time savings of almost 60 per cent are being achieved on the N40 to N25 route during peak hours, while time savings of over 50 per cent are being achieved on routes accessed via the M8 Southbound.
Peter Walsh, chief executive of Transport Infrastructure Ireland, said that the project marks the culmination of a journey that has been ten years in the making.

The project is not without its issues. There have been complaints that the signage is unclear; in particular when northbound out of the N40 tunnel, the right-hand exit for M8 is very sudden. This is due to lack of room but advance signage would be prudent as motorists have little time to get ready.
The N25 to N40 Tunnel movement has very little room since the tunnel is only 2 lanes each way. The onramps from before and right at the new Little Island junction are a total of 3 lanes, but this is reduced to only 1 which then becomes one of the tunnel lanes, the other being for the M8 Southbound flow. Already this has been causing queuing issues, but little can be done without drilling another tunnel bore.
The west-east cycle lane does not underpass the junction but forces cyclists up to L2998 here where they must double-back before passing under the M8, then through a series of roundabouts before finally getting to L3004 where it can use the old road up to Glounthane and beyond. An underpass of the Dunkettle Roundabout to M8 slip road at this location would have allowed bikes to head east for a far more direct route.

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Wikipedia page on this road

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Traffic Counts for this road: Old N8, New M8


Origin M7 Junction 19, Aghaboe, Southwest of Portlaoise
Terminates Horgan's Quay and Ship St, Cork
Places Served Abbeyleix, Urlingford, Cashel, Cahir, Mitchelstown, Fermoy, Glanmire, Cork
Routes Spawned -
Intersects M7, N24, N25


Section km Opening Date Standard
Jct 18-19 Glanmire 7.5 1992-04-03 M (from 2009-08-28)
Jct 17-18 Watergrasshill 10 2003-09-12 M (from 2009-08-28)
Jct 7-9 Cashel BP 7 2004-10-11 M (from 2008-09-24)
Jct 14-17 Fermoy 18 2006-10-02 M
Jct 9-10 Cashel-Cahir 12 2007-10-15 M (from 2008-09-24)
Jct 10-12 Cahir-Mitchelstown 28 2008-07-25 M (from 2008-09-24)
Old N8-Jct 4-7 Cullahill-Urlingford-Cashel 40 2008-12-08 N section: M,
S section: M (from 2008-09-24)
Jct 12-14 Mitchelstown-Fermoy 16 2009-05-25 M (from 2009-08-28)
Jct 1-3-Old N8 Aghaboe-Cullahill
  (as M7/M8 Portlaoise)
14 2010-05-28 M
Jct 19 Dunkettle Interchange Upgrade 2024-02-12 INTERCHANGE