ROAD CLASSES

An introduction to and explanation of the route classification scheme used in the Republic of Ireland.

What classes of road are there?

There are between three and five major route classes or designations; I'll explain below. In theory, the road standard should reflect the road class, but in Ireland, this isn't really the case. There are sections of dual carriageway under all classes, and as of 2006, some bits of the most important routes in the country are narrow winding badly paved country roads.

So what are the most important routes?

The most important routes are called national roads. These are all given route numbers of one or two digits, with the route number generally speaking prefixed with N - for national road. There are two distinct classes within that broader class. National primary roads are the most important, starting with the N1 and up to N33; there's another national primary route I'll mention specially in a bit. National secondary roads are, well, secondary. They are numbered from N51 and up. The National Roads Authority is directly responsible for national roads in the state.

Where do motorways come into it all?

Motorways aren't an alternative to the route classes mentioned above. As of 2006, all motorways in the Republic form part or all of a national primary road. In theory, any other road (like a national secondary road) could just as easily have a motorway section. Motorways are given a special route designation - they use the M prefix before the route number. So a motorway along, say, the N7, is numbered the M7. There is one interesting case, the M50 (you know, that awful car park around Dublin); it is in fact a national primary road, the N50. As it is entirely motorway though, the N prefix isn't ever used. The number is also out of sequence, at the time it was planned/built, a number in the low thirties would have been the next one to allocate. Fifty is more distinctive though, so that was used.

So, that's national roads and motorways; what else is there?

Some of the more prolific components of the route network that are of consequence are regional roads. These form a criss-crossing network between the national roads, ensuring the whole country has good access to the national road network. Regional roads are numbered with three digits, and use the prefix R. In theory regional roads should be decent road links - but as they are dependant on county-level funding/allocations, the standards vary wildly. Just about everything from dual carriageways to donkey tracks exists as an R road!

The poor relations of all these roads are what are usually described on maps as "other roads". In fact, they are called local roads, and are numbered. They use four digit route numbers, with a prefix of L. Until recently, these numbers were a bit of a secret, and didn't appear on signs or maps. A new signage update scheme though has seen a change of policy, and L numbers will appear on a lot of road signs from now on. Again, county councils are pretty much entirely responsible for local roads.

What are the differences between the classes?

Well, apart from any of the details above, there are different "default" speed limits for the road classes. National roads usually allow you to travel at 100 km/h in the absence of local restrictions, while on any other roads, the maximum you'll ever be allowed to travel is 80 km/h. Motorways usually allow 120 km/h travel, and since new laws were brought in, even other dual carriageways (non-motorway) can have this limit applied to them specially (as of Sept. 2006, this has only been done on the N2 north of Dublin).

The other difference you might notice is directional road signs. On a motorway these are generally blue with white text (there are exceptions, both valid and invalid). On national roads, both primary and secondary, the signs are mainly green with white text and amber route numbers. Other roads use white signs with black text.

On the green signs, and on the white signs, if the directions are to a destination served by a route of a different class, then a patch of a different colour is applied to the sign. So on a national road, a destination reached by following a motorway will appear on a blue patch on the green sign.

Again - this is in theory - you'll notice that things sometimes have the appearance of someone having guessed at what kind of sign to use. And there are some truly bizarre mixtures in places. But in general, blue=motorway, green=national road, white=regional or local road.