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

KrisW1001 · 21-12-2024 10:54PM

https://www.boards.ie/discussion/comment/122981231#Comment_122981231

Yes, 2+1 was withdrawn from the set of standards.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

Paddico · 10-01-2025 01:11PM

https://www.boards.ie/discussion/comment/122981082#Comment_122981082

Why would safety come into it.

Cookiemunster · 10-01-2025 01:18PM

https://www.boards.ie/discussion/comment/123041044#Comment_123041044

Because safety always comes into it. It's one of the basic principles of road design. With 2+1s drivers were racing to overtake traffic and cutting in at the last minute before the overtaking lane ended and therefore causing accidents. Plus the at grade junctions were a death trap.

steeler j · 15-01-2025 01:39AM

PHase 3 is 60% completed . Draft design is expected in Q1 2025 . ABP hoped for Q4 2025 . That's the latest I have heard on it .

Paddico · 16-01-2025 02:35PM

https://www.boards.ie/discussion/comment/123041065#Comment_123041065

Ah .. that type of road. My god

marno21 · 06-03-2025 01:45AM

The project is currently progressing through the design and environmental evaluation phase, during which detailed design of the project is undertaken, along with the preparation of land acquisition documentation and surveys. Transport Infrastructure Ireland has advised my Department that it is anticipated that this phase will conclude in the second half of this year, after which a preliminary business case will be submitted to my Department, as per the infrastructure guidelines.
With regard to the fast-tracking of individual elements of the overall project, the delivery programme will be clearer once the current project phase has concluded. However, my officials will continue to engage with TII with regard to this project, including, I can assure the Deputy, on the feasibility of fast-tracking elements of the project such as the Tipperary town bypass.
Subject to the Government's approval of the preliminary business case, the project will then proceed through the statutory processes, which will include an application for planning approval to An Bord Pleanála. It is expected that this application will be made in the first half of 2026.

Business case to the Department in H2 2025, ABP in H1 2026.

marno21 · 08-03-2025 06:04AM

According to Darragh O'Brien's incoming Ministerial brief, this is to be submitted to Govt for Cabinet approval to submit to ABP in Q4 of this year. ABP submission will follow shortly after.

Exiled Rebel · 08-03-2025 08:33AM

This can't be done quick enough. I travelled this route at an average speed of 60kph a couple of weeks ago. It's an absolute pain when you get stuck behind a slow moving lorry.

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

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