The island of Ireland, comprising Northern Ireland and the Republic of Ireland, has an extensive network of tens of thousands of kilometres of public roads, usually surfaced. These roads have been developed and modernised over centuries, from trackways suitable only for walkers and horses, to surfaced roads including modern motorways. Driving is on the left-hand side of the road. The major routes were established before Irish independence and consequently take little cognisance of the border other than a change of identification number and street furniture. Northern Ireland has had motorways since 1962, and has a well-developed network of primary, secondary and local routes. The Republic started work on its motorway network in the early 1980s; and historically, the road network there was once somewhat less well developed. However, the Celtic Tiger economic boom and an influx of European Union structural funding, saw national roads and regional roads in the Republic come up to international standard quite quickly. In the mid-1990s, for example, the Republic went from having only a few short sections of motorway to a network of motorways, dual carriageways and other improvements on most major routes as part of a National Development Plan. Road construction in Northern Ireland now tends to proceed at a slower pace than in the Republic, although a number of important bypasses and upgrades to dual carriageway have recently been completed or are about to begin.
The N7 road is a national primary road in Ireland, connecting Limerick and Dublin. The majority of the route is motorway standard and is designated as the M7 motorway. At the Rosbrien interchange in Limerick the route continues as the N18 dual carriageway to Galway, Shannon and Ennis. The road passes through the midlands of Ireland, and acts as a trunk route out of Dublin for the N8 and N9 national primary routes to Cork and Waterford respectively. It forms part of European route E20.
The N8 road is a national primary road in Ireland, connecting Cork with Dublin via the M7. The N8 is further classified by the United Nations as the entirety of the European route E 201, part of the trans-Europe International E-road network. The road is motorway standard from junction 19 on the M7 to the Dunkettle interchange in Cork City and is designated as the M8 motorway. From here the route continues into Cork city centre and terminates at the N22 road at St. Patrick's Street. The M8 motorway was completed in May 2010, replacing the single carriageway sections of the old N8 and bypassing towns on the main Cork to Dublin road. It is now possible to travel from Cork to Dublin on the M/N8 in about 2 hours 30 minutes. The route commences just south of Portlaoise, and reaches Cork via the midlands and the Golden Vale of Ireland, through Counties Laois, Kilkenny, Tipperary, Limerick and Cork.
The N11 road is a national primary road in Ireland, running for 129 km (80 mi) along the east side of Ireland from Dublin to Wexford. It passes close to Bray, Greystones, Wicklow, Arklow, Gorey, and Enniscorthy. Beyond Wexford, the route continues to Rosslare as the N25. The road forms part of European route E01. As of July 2019 the N11/M11 is of dual carriageway or motorway standard from Dublin as far as Oilgate in County Wexford.
The N4 road is a national primary road in Ireland, running from Dublin to the northwest of Ireland and Sligo town. The M6 to Galway diverges from this route after Kinnegad, while the N5 to Westport diverges at Longford town. Most sections of the N4 that are motorway-standard are designated the M4 motorway.
A dual carriageway (BrE) or a divided highway (AmE) is a class of highway with carriageways for traffic travelling in opposite directions separated by a central reservation (BrE) or median (AmE). Roads with two or more carriageways which are designed to higher standards with controlled access are generally classed as motorways, freeways, etc., rather than dual carriageways.
The N6 road is a national primary road in Ireland from junction 11 on the M4 motorway at Kinnegad to Galway city. The N6 and N4 form a continuous motorway or dual carriageway from Dublin city centre to Galway City passing in an east–west direction through the midlands of Ireland. Most of the road is motorway standard with the exception of the Athlone bypass and stretches of urban road in Galway City, which are the only sections of the road that remain designated as N6 dual carriageway. There is one toll on the road outside Galway city. Major upgrades to the road were completed in December 2009 completing the first intercity motorway/dual carriageway in Ireland and the New Junctions of M6 are built and will be 164 km.
The N2 road is a national primary road in Ireland, running from Dublin to the border with Northern Ireland at Moy Bridge near Aughnacloy, County Tyrone to connect Dublin with Derry via the A5. A section of the route near Dublin forms the M2 motorway.
The road hierarchy categorizes roads according to their functions and capacities. While sources differ on the exact nomenclature, the basic hierarchy comprises freeways, arterials, collectors, and local roads. Generally, the functional hierarchy can more or less correspond to the hierarchy of roads by their owner or administrator.
The N18 road is a national primary road in Ireland, connecting the cities of Limerick and Galway. Ennis and Gort are two major towns on the route, and Shannon Airport is reached via the connecting N19. The west coast route continues on to Sligo as the N17. The section from Limerick to the N19 junction forms part of European route E20, and the entire route is part of the proposed Atlantic Corridor. The section of motorway from Shannon to Claregalway is designated the M18 motorway. The tolled Limerick Tunnel forms part of the route.
The N19 road is a national primary road in Ireland, connecting from the N18 Limerick–Ennis–Galway road to Shannon Airport. It forms part of European route E20.
The N20 road is a national primary road in Ireland, connecting the cities of Cork and Limerick. Buttevant, Croom, Charleville, Mallow and Blarney are major towns along the route. A short section of the route is motorway standard and is designated as the M20 Motorway.
The N25 road is a national primary road in Ireland, forming the route from Cork to Rosslare Europort via Waterford City. The road is part of the E30 European route and a short section is also part of the E01 European route. It forms part of the proposed Atlantic Corridor route.
A national primary road is a road classification in Ireland. National primary roads form the major routes between the major urban centres. There are 2649 km of national primary roads. This category of road has the prefix "N" followed by one or two digits. Motorways are prefixed "M" followed by one or two digits.
The A452 is a road in England, which runs from Royal Leamington Spa, Warwickshire to Brownhills in the West Midlands. It is the major link to the M6 motorway for both Leamington and Warwick in addition to serving as Leamington's link to the M40 motorway and to Coventry.
A High-quality dual carriageway (HQDC) is a road category in Ireland. It is defined as an all-purpose dual carriageway road type built to near motorway standards, but without motorway classification or motorway restrictions. High-quality dual carriageways have full grade-separated access and do not have junctions with minor roads. Such roads in the Republic of Ireland have been built as part of the 2000–2006 and 2007–2013 National Development Plans, including interurban routes from Dublin to other cities.
The A3220 is a primary A road in London, England. It runs north from Clapham Common to the A40 Westway at Ladbroke Grove.
The N73 road is a national secondary road in Ireland. It is made up entirely of single carriageway with few overtaking opportunities and only a small amount of hard shoulder.
The M6 motorway is a motorway in Ireland, which runs from Dublin to Galway. The M6 extends from its junction with the M4 at Kinnegad all the way west to the outskirts of Galway City, but the Athlone bypass and the approach to Galway city - while of dual carriageway standard - have not been designated motorway and are still signed as N6. The motorway was officially completed and opened to traffic on 18 December 2009, and was the first city-to-city direct major inter-urban route to be completed in Ireland. The M6 and M4, which form the Galway-Dublin route, consist of a grade-separated 2+2 dual carriageway road with a top speed limit of 120 km/h. At approximately 144 km (90 mi), the M6 is the third longest motorway in the state and will be 159 km.
The M18 motorway is an inter-urban motorway in Ireland, forming part of the Limerick, Ennis to Galway national primary road, which, in turn, forms part of the Atlantic Corridor called for as part of the Transport 21 project.
A523.
A538 
A5144 
A5103 
M56 
A34 
A5149 
A5145 
A6 
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A57 