Motorways in the Republic of Ireland

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 also several three-lane motorways, while Ireland's busiest road, the M50,^[1] incorporates four-lane, five-lane,^[2] and six-lane^[3] stretches.

The completion of the Major Inter-Urban Motorway Project in December 2010, which saw Dublin connected to the cities of Cork, Limerick, Waterford and Galway by continuous motorway, as well as a number of other projects, increased the total length of the country's motorway network to 916 km. Planned new road construction will possibly lead to there being almost 1100 km of motorway by 2035, subject to the availability of funding.