Road classifications

Ireland has a comprehensive road network, consisting of around 100,000 kilometres of routes of varying standards and importance.

Those roads that form part of the classified network are numbered according to thier status, whether they are trunk routes managed by the state, or local roads that are looked after by the local county councils.

Motorway

As part of the national route network, the 916km of motorways form a high speed network across Ireland - although most are routes radiating out of Dublin towards the major towns and cities.

The Irish Republic was a latecomer to the motorway, the first of which being the M7 Naas Bypass which opened in 1983. This was quickly followed by the M1 to the north of Dublin.

Expansion was low until the 1990s, when a number of stretches of motorway opened across the country, mainly consisting of various town bypasses. This decade also saw the opening of the first parts of the M50 Dublin Ring Road.

The biggest push came during the 2000s, when large stretches of new motorway opened (some tolled), aided by private funding through public-private partnerships. Much of this saw many of the bypasses linked together  and a huge amount existing dual carriageway trunk routes reclassified.

There hasn't been as much new motorway built in the past few years, however there has been some - principally the opening of the M17/M18 as part of the Atlantic Corridor project to improve connections along the west coast.

National Roads

These form the strategic trunk road network, much of which has been upgraded to motorway standard. There are over 53,000km of these roads, which are split into two groups - national primary and national secondary routes.

National primary routes are the major trunk routes that link the principal urban centres. These are numbered 1 to 50 with four distinct clusters:
 - 1 to 11 : radial routes from Dublin;
 - 12 to  26 : provincial cross-country routes;
 - 27 to 33 : feeder routes (mainly to/from ports);
 - 40 & 50 : city bypasses (Cork and Dublin).

National secondary routes are less important than the primaries, but nonetheless provide important cross-country links across the country. These roads are numbered 51 to 99.

They tend to be of a lower standard than their primary counterparts, generally because traffic volumes are lower. They are often narrow with many twists and turns, but their routes through spectacular scenery make them popular with tourists (and thus add to their importance, especially economically).

Regional Roads

There are over 11,000km of reginonal roads in Ireland, providing a newtork of important routes that link together the smaller towns to each other, as well as the national network. These roads are all given three-digit route numbers.

Local Roads

All other public roads are classified as local roads, regardless of their use or importance - this includes little back lanes and cul-de-sacs buried deep in housing estates.

Local roads are split into three groups - local primary, local secondary and local tertiary. Such roads are given 4, 5 or 6 digit roads dependent on their group. Numbers are generally not shown on signage, however there is an increasing tendency to show them on direction signs where they can help with navigation (especially with local primary routes). Numbers are allocated on a regional basis, so they do appear in more than one area and may change where a road crosses a county boundary.

Euroroute

Some national primary routes and motorways form part of the UN's international Trans-European Road Network. Where this the case, the road concerned is given an additional route number (or in some cases, two where thery run concurrently).

To show this status, supplementary green cartridges appear on route confirmation signage alongside the regular A- or M- road number, for example  M 1   E-01 .