N24 - Cahir to Limerick Junction [design and planning underway]

Full exchange between Mattie McGrath and Ryan.

https://www.oireachtas.ie/en/debates/question/2024-07-04/3/#pq-answers-3

The maps together with updates etc are available on the project website.

https://n24cahirlimerick.ie

It won’t meet the upgraded circa year 2000 section (I think it’s a turn off for Cappamore) then? That’s a fairly decent section of route from there to Limerick city ring road- albeit decent single carriageway with a hard shoulder and straight

design update 2 up on the website now

They really should be facilitating trains from Waterford entering LJ station from the Cork side, seeing as the road will be going that side and major construction will be required. The active travel component seems very piecemeal, I thought it would have to be along the full length of new road.

That's insane, the cost savings would be minimal as presumably the same level of grade separation would be needed for 2+1 as 2+2, since both have a median barrier.

Yes, 2+1 was withdrawn from the set of standards.

The 2+1 pilot schemes, particularly on N20 south of Mallow, showed an increased risk of accidents at the end of the 2-lane sections. Obviously, it was still deemed safer than the single carriageway it replaced, because the 2+1 has not been removed.

(I always thought that that N20 scheme was an innapropriate use of the road type: in its native Sweden, 2+1 was only used on lightly trafficked rural routes where the main danger was from cars unsafely overtaking slower agricultural vehicles, but on N20 they tried to use it as a cheap capacity fix. N2 Castleblaney-Clontibret is much closer to the intended use case)

As for cost, Type 3 (2+1) was significantly cheaper, because unlike a Type 2 (2+2), the original Type 3 DC specification did not require grade separation or roundabouts for all junctions: for minor junctions, it was permitted for right-turning traffic to cross the median. This was a big cost saving compared to 2+2, especially when retrofitting existing wide single carriageway, but of course it wasn't as safe as the stricter junction policy for Type 2 DCs.

On a new-build road like this one, though, where there are few junctions, 2+1 wouldn't save a lot of money compared to 2+2... why bother for the sake of saving 2 metres of paved width? .

Ah .. that type of road. My god