The N52 upgrade, described elsewhere on this site, is a highly important cross-country connector - but its intention is to run diagonally across the country connecting the southwest with the northeast. It hits a point just shy of the M1 halfway between Dundalk and Drogheda, bringing traffic within spitting distance of the border and eventually Belfast. For Drogheda-bound traffic, the N51 road splits off and heads east. This route also serves as the main Navan-Drogheda road.

The proposed Leinster Outer Orbital Route will provide a motorway along the latter corridor which will serve the movement for long distance traffic and local traffic that doesn't mind paying the toll, but a non-tolled, non-motorway road will still be needed. The N51 as it currently exists is completely inadequate for the purpose. A new single-carriageway replacement will be needed.

Such a route is essential from a heritage point of view too, as the road currently runs through the Boyne Valley World Heritage site with its Newgrange ancient megalithic monument, older even than the Pyramids of Egypt, as well as the picturesque town of Slane, with its famous castle, frequently used as a concert venue.

The proposed route below runs to the south of the Boyne, avoiding the whole valley with its scattered megalithic structures, and Slane. It connects to the M1 at junction 9 instead of 10 currently.

As for numbering, normally in Ireland a motorway replaces any national routes that parallel its path, and this route will be paralleled by the Leinster Outer Orbital. So although the new Navan-Drogheda road should be a new build, it should not be a National route, but a Regional (R) one - number to be assigned. All of the existing N51 would be downgraded to Regional status too, as indicated by the pins in the map below.

Please give your opinion on this road proposal. Rate it out of 10, and whether you think the standard (road width) is appropriate.

Wikipedia page on the N51 which this would replace