National Primary Route 40

The Leinster Outer Orbital or Dublin Outer Orbital Road is a long motorway bypass proposed for Dublin. Its primary purpose is to relieve the M50 of the duty of carrying long distance traffic, leaving it as a distributor road for the city.

This long motorway was initially described as being around 100 km long, then 80km. Based on rough alignments identified so far, its length will be close to 74 km. It does not have funding under the current Transport21 plan. This means that only route selection and other basic work can take place on it up to 2015. However, the government has repeatedly reaffirmed that this motorway is a priority and will be undertaken after 2010 when the interurbans are finished. Considering funding was not set aside, and certainly cannot be in the current economic climate, this seems unlikely, and a 2020 opening date is more realistic.

The road is estimated to cost €2B and will be tolled.

Note the the road does not have a confirmed number yet. The road is most commonly known as the Leinster Outer Orbital or the Dublin Outer Orbital Road (DOOR). Its number can be predicted to be 40 because of the following logic:

• It must be a National Primary Route, which limits its number to 1-50
• Only numbers 34-49 are free
• Being such an important route, and a complement to the M50, it should end in a zero or a five, numbers which tend to denote importance.
• The only such numbers available are 40, 35, and 45.

Therefore the DOOR is likely to be labelled M40.

Like the M50, the M40 is a new build road and does not replace an existing route. There is no N40 at present, just as there has never been an N50.

New roads in the hinterland of a major city always attract new commercial and industrial development. Sure enough, it seems that the lands abutting the future corridor are already in demand.

Wikipedia page on this road