In Ireland, the highest category of road is a motorway (mótarbhealach, plural: mótarbhealaí), indicated by the prefix M followed by a one- or two-digit number (the number of the national route of which each motorway forms a part). The motorway network consists entirely of motorway-grade dual carriageways and is largely focused upon Dublin. There are several three-lane motorways. Ireland's busiest road, the M50, incorporates four-lane, five-lane, and six-lane stretches.

The completion of the Major Inter-Urban Motorway Project in December 2010, connected Dublin to the cities of Cork, Limerick, Waterford and Galway by continuous motorway, as well as a number of other projects, increased Ireland's motorway network to 916 km. Planned new road construction will possibly lead to almost 1,100 km of motorway by 2035, subject to the availability of funding.

Features

Regulations Motorways in Ireland have a set of restrictions,Rules for driving on Irish motorways which prohibit certain traffic from using the road. The following classes of traffic are not allowed on Irish motorways:

Learner drivers Slow vehicles (i.e. not capable of reaching 50 km/h (30 mph) on a level road) Invalid carriages (lightweight three-wheeled vehicles) Pedestrians Pedal-cycles (bicycles, etc.) Vehicles under 50cc (e.g. mopeds) Vehicles without pneumatic tyres Animals

Rules for driving on motorways include the following: The keep-left rule applies unless overtaking No stopping at any time No reversing No hitchhiking Only vehicles that can travel faster than 90 km/h (55 mph) may use the outside lane No driving on the hard-shoulder

The general motorway speed limit is 120 km/h (75 mph).

Specification

Motorways in Ireland are generally constructed to high-quality dual carriageway standard – with sightlines, curves and elevation designed for 120 km/h speeds. Until recently, all motorways were built with wide medians in the centre, which typically have a wire or steel barrier with a continuous hedge growing and covering it over time. The more recent schemes have narrow medians, only 3 metres in width, with a concrete barrier in the middle.

These narrow-median schemes have reduced carriageway width – a typical narrow-median motorway cross section has two 3.5-metre running lanes, a 2.5-metre hard shoulder and a 1.5-metre central reserve in each direction. A typical wide median motorway has 3.75-metre running lanes and a 3-metre hard shoulder.

Ireland has only a small amount of D3M, a motorway with three lanes in each direction. The M50 is the most notable example, upgraded in parts from a two-lane motorway, to a three or four lane motorway in each direction.

Apart from terminal junctions, motorways can only be accessed using grade-separated junctions. These typically take the form of roundabout interchanges for higher-capacity junctions, or dumbbell interchanges – which are a variant on the diamond-style interchange – for lower-trafficked interchanges. Other types of junction are also used on the motorway network. The M4/M6 and M7/M9 junctions use a variant of the fork style interchange. The M9/N10 junction in County Kilkenny and N40/N28 junction in Cork City are trumpet-style interchanges. The M50/N7 and M50/N4 interchanges use partial cloverleaf junctions.

Safety

Motorways in Ireland include several safety features not found on other classes of road. The most notable include the presence of a continuous hard-shoulder, use of crash barriers, superior lighting and provision of emergency phones at regular intervals. Some motorway schemes include deflectors to provide protection at interchanges.

Signage

Motorway signage in Ireland is blue, and is similar in design to UK signage. Signs for on-line service areas are blue. Those for off-line service areas are brown. Route numbers use the Motorway typeface. All other text uses the Transport Heavy typeface, with Irish text being rendered in a unique oblique variation.

Signs featuring the motorway number and motorway symbol are positioned at the entrances to motorways, generally on both sides of the slip road. When approaching a junction that leads to a motorway, signs indicating motorway restrictions may be placed in advance.

Route number inheritance

In Ireland all motorways form part of a national route. The M50 was the only motorway that initially did not form part of an existing national primary route, though it was designated as the national primary route N50 in 1994.

In most cases, motorways were built to by-pass a road forming the national road. For example, the M7 by-passes roads previously forming the N7. The by-passed roads are then generally reclassified as regional roads. Motorways are sections of roads with special regulations, and they are signposted with the M prefix to indicate that they are under motorway regulations.

Present network

The following table shows a list of motorways currently open in Ireland.

RouteMotorway sectionDestinationsToll M50 to north of Dundalk. Dublin – Belfast J7 – J10 Killshane to north of Ashbourne. Dublin – Derry - Clonee to north of Kells. Dublin – Ballyshannon J5 – J6, J9 – J10 Lucan to Coralstown, Mullingar Dublin – Sligo J8 – J11 M4 Junction 11 (Kinnegad) to east of Athlone; west of Athlone to Galway Dublin – Galway J15 – J16 Naas to Limerick. Dublin – Limerick J18 – J21 M7 Junction 19 (c. 15 km south-west of Portlaoise) to Cork. Dublin – Cork J1 – J3, J14 – J17 M7 Junction 11 (c. 8 km south-west of Naas) to Quarry roundabout, Grannagh, Co. Waterford Dublin – Waterford - Shankill/Bray Bypass; Ashford to north of Oylegate. Dublin – Wexford - East of Galway to south of TuamGalway – Sligo - Shannon, County Clare to east of Galway. Limerick – Ennis – Galway J2 - J4 (N18) Outskirts of Limerick City to Patrickswell, (Remainder to Cork Planned) Cork – Limerick - Dublin Port to Shankill Dublin ring road J1 – J2, J6 – J7

History

1983–1989 In 1983, the first sections of Irish motorway were opened: a short section of M7 bypassing Naas and the first stretch of M1, all of which has now been redesignated M50. In 1985, the M1 was extended to Dublin Airport.

1990–1999 Ireland's motorway network began to expand significantly between 1990 and 1999. The first of the projects completed in this period was the western section of the M50, linking the N7, N4 and N3 together in 1990. This was quickly followed by the M11 Bray/Shankill bypass in 1991. After this there followed a lull in construction after what had been a busy few years in motorway construction by then Irish road building standards. 1993 saw an extension to the M7, continuing from the Naas Bypass and providing a bypass of the town of Newbridge, and the M9 Kilcullen spur. Another small section of M1, a bypass of Dunleer in County Louth was opened.

In 1994, the Leixlip to Kilcock motorway was completed, forming part of the M4. In 1995, no new motorways were opened. In 1996, the northern section of the M50 was opened, linking the existing motorway to the N2 and M1. In 1997, the Portlaoise bypass opened as M7, and, like the M1 Dunleer bypass, seemed very isolated compared to the rest of the network which was concentrated around Dublin. 1998 saw the opening of another short piece of M1, this time to the south of Balbriggan, modern day junctions 5 and 7. In 1999, there were no new sections of motorway opened.

2000–2010

The 2000s saw a major expansion in the construction of new motorways in Ireland, after an initially slow start. In 2000, no new motorways opened. In 2001, another section of the M1, extending the Dunleer bypass northwards to the south of Dundalk (junction 16), and the M50 Southern Cross Route were opened. In 2002, no new motorways opened.

In 2003, the sections of the M1 were joined, creating a continuous motorway from Dublin to just south of Dundalk. A huge part of this route was the Drogheda bypass which was tolled. Also in 2003, the M7 was extended westwards from Newbridge to also bypass Kildare, up to modern day junction 14. In 2004, it was extended further with the opening of the Monasterevin bypass to link up with the Portlaoise bypass. This meant there was now a continuous motorway from Naas to Portlaoise.

In 2005, the M4 was extended from Kilcock to Kinnegad, with a toll applied to it, one of the first PPP schemes to be tried out in Ireland. The M1 Dundalk bypass was also finished, meaning that there was now a full motorway link on the Dublin to Belfast route virtually as far as the border. In 2005, the M50 was extended to link up to the M11, providing a full western bypass of the capital.

In 2006, the M8 Fermoy to Watergrasshill motorway was opened, another section that was tolled. In 2006, a section of what would become M6 was completed, going westwards from the M4 at Kinnegad to Tyrrellspass. The road was opened as N6 and was the first section of road to be completed that would be affected by the Roads Act 2007 and motorway redesignation.

In 2007, the same road was extended by some 10 km (6 miles) to join with the N52 north of Tullamore, still opened as N6, as the first tranche of motorway redesignations had only just been submitted.

In 2008, a large section of the M8 opened, making it the longest motorway in Ireland. Stretching from Urlingford to just east of Mitchelstown, the motorway opened in sections, the first being the Cashel bypass, which opened in 2004, and which was followed by the Cashel to Mitchelstown section, both of which were open before the redesignation to motorway came into effect in September 2008. The Urlingford to Cashel section opened later on in the year and so became a motorway immediately. Also opened in 2008 was the M9 Carlow bypass which was also open to traffic before the redesignation came into effect. The M6 was extended to the Athlone bypass and Ireland's motorway network was greatly expanded.

2009 was another major milestone in the development of the Irish motorway network, with many projects under construction finished by the end of the year. Redesignation of High-Quality Dual-Carriageway sections of National Primary routes to motorway took effect on 28 August 2009, further expanding the network. On 18 December 2009 the M6 was opened (Dublin-Galway direct). It is 194 km (120 miles) of motorway. The M9 (linking Dublin to Carlow) was opened on Monday 21 December 2009 and was expanded in March 2010 to link Dublin to Waterford directly. The M9 was fully completed with the opening of the Carlow to Knocktopher section on 9 September 2010.

2010: M3: 61 km (38 miles) of motorway in County Meath opened on 4 June 2010.

M7: Nenagh – Limerick, 38 km (24 miles) long, opened in three stages, being fully opened on 28 September 2010.

M7: Limerick – Shannon motorway tunnel, 10 km (6 miles) long, opened ahead of schedule on 27 July 2010.

M7: Castletown – Nenagh, 36 km (22 miles) long, opened 22 December 2010.

M7/M8: Portlaoise – Castletown, Portlaoise to Cullahill, 40 km (25 miles), opened on 28 May 2010.

M9: Carlow – Knocktopher, 40 km (25 miles) long, opened 9 September 2010.

M9: Knocktopher – Waterford, 24 km (15 miles) long, opened 22 March 2010.

M50: improvements for Dublin, completed August 2010, but expected earlier.

M18: Crusheen and Gort, 22 km (14 miles), opened 12 November 2010.

Motorway redesignation (tranche 1) The Roads Act 2007 was passed into law in mid-2007. This Act makes provision for the redesignation of suitable dual carriageways to motorway status. The National Roads Authority made formal applications under Section 8 of the Act to the Minister for Transport on 16 October 2007 regarding dual carriageways which the authority believed to be suitable for redesignation as motorways.

On 29 January 2008, the Department of Transport published notice of the Minister's intention to make the orders being sought and invited submissions or observations to be made to the Minister regarding the NRA's applications.