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

marno21 · 09-12-2019 10:46pm

Christy Browne wrote: »

Surely it would make more sense to do a dual carriageway the whole way between the two cities of Limerick and Waterford than this piece-meal patch up job?

That's the long term plan, but the current plan is to advance two independent sections, one between Limerick Junction and the M8, and the other between Cahir East and Waterford.

Limerick Junction-Waterford would be too big on its own.

steeler j · 18-09-2020 11:02am

This is about to start phase 2 soon ,they lost time during covid 19 lockdown but are hopeful of having public consultations in January

Paddico · 22-09-2020 1:48pm

Any link to this bit of news Steeler?

Limerick74 · 22-09-2020 2:10pm

steeler j wrote: »

This is about to start phase 2 soon ,they lost time during covid 19 lockdown but are hopeful of having public consultations in January

Sounds unlikely unless just a consultation for constraints study. These things take time and it’s a big scheme.

steeler j · 22-09-2020 5:08pm

Limerick74 wrote: »

Sounds unlikely unless just a consultation for constraints study. These things take time and it’s a big scheme.

Local poltian announced it on social media ,it looks like it is consultations are for constraints study

steeler j · 22-09-2020 5:12pm

Paddico wrote: »

Any link to this bit of news Steeler?

I don't have ,just local councillor announcement on social media

steeler j · 15-10-2020 1:53pm

A website about to be launched soon on the scheme

steeler j · 15-10-2020 2:06pm

Q2 2021 for route options

Paddico · 16-10-2020 1:08pm

Thats great but seems like a very aggressive timeline

spacetweek · 16-10-2020 9:26pm

Surprisingly the TII have indicated that this scheme will be a 35 km motorway, the M24.

marno21 · 16-10-2020 9:29pm

spacetweek wrote: »

Surprisingly the TII have indicated that this scheme will be a 35 km motorway, the M24.

Not sure of the logic there that this would be motorway and the stretch east of Cahir won’t be. The N24 between Tipp Town and Cahir is carries less than half the traffic of east of Cahir. If east of Cahir was dualled it would also take some traffic off the N72 and N25.

steeler j · 16-10-2020 10:02pm

spacetweek wrote: »

Surprisingly the TII have indicated that this scheme will be a 35 km motorway, the M24.

A surprise,I was hoping for a type 2 dual carriageway

BelfastVanMan · 16-10-2020 10:27pm

steeler j wrote: »

A surprise,I was hoping for a type 2 dual carriageway

It will probably make more sense when the final piece, Ballysimon to Limerick Junction, is built.
Presumably it will be Type 1 DC also, and then it will be M24 from Limerick to Cahir.

steeler j · 16-10-2020 10:43pm

BelfastVanMan wrote: »

It will probably make more sense when the final piece, Ballysimon to Limerick Junction, is built.
Presumably it will be Type 1 DC also, and then it will be M24 from Limerick to Cahir.

Yes ,the study area goes west of oola

KrisW1001 · 16-10-2020 11:34pm

How does traffic volume on that corridor (Rosslare - Limerick) justify a motorway (Type 1) cross-section? 2+2 (Type 2) would be an excellent solution, and I would be amazed if anything bigger was built.

N25, a much more trafficked route, connecting larger population centres, is still Type 1 Singla carriageway for most of its length between Waterford and Cork.

spacetweek · 17-10-2020 2:45pm

Indeed I'd worry that if the anti-M20 brigade got wind of this they'd scream that you don't need an M20 if there's going to an M24 Limerick-Cahir as that could be used for Limerick-Cork journeys.

I really don't see the need for a motorway here.

steeler j · 17-10-2020 2:51pm

spacetweek wrote: »

Indeed I'd worry that if the anti-M20 brigade got wind of this they'd scream that you don't need an M20 if there's going to an M24 Limerick-Cahir as that could be used for Limerick-Cork journeys.

I really don't see the need for a motorway here.

Great point

Pete_Cavan · 17-10-2020 4:33pm

Would a M24 become the primary route between Waterford and Cork (via M8), in one or both of most people's preferred route and designation/signing? The Waterford bypass toll may mean TII/government dont want to do this. Adding that traffic might justify motorway. Maybe send it south of Cahir and tie into an upgraded M8 J11. Could revise the N25 west of Waterford to a national secondary and the N24 become N/M25 which would run from Wexford to Limerick via Waterford? It would tie together much of motorway network, linking M7, M8, M9 and M11, plus M18, M20 and M21.

Chris_5339762 · 18-10-2020 10:49am

It would be an alternative... there'd be little difference in the time if the M24 existed.

However you have the Fermoy toll to think about as well, and quite a bit of extra distance. That said, its less of a diversion than you might think doing geography in your head.

steeler j · 18-10-2020 11:19am

I think Cork to Waterford via the m8/n24 is about 19 km more

KrisW1001 · 18-10-2020 12:15pm

Waterford-Cork via N24 is a long detour (15% furhter) along a road that is much, much worse than the N25, and it would also funnel Waterford and Rosslare-originated traffic onto what is already the busiest arm of the Dunkettle interchange when it gets to Cork. Not a good idea.

N25 is also the Irish part of Euroroute E-30, so its status as the main route between Rosslare and Port of Cork is assured.

On the type of road, Type 1 has to be a mistake. The recent presentation (https://www.tii.ie/tii-library/conferences_and_seminars/nrc/nra-nrc-2019/12-Eoin-Doyle-Arup-Presentation.pdf , page 17) on 2+2 expressways gives traffic counts in 2018 for the two N24 sections up for improvement.

N24 Cahir to Limerick Junction 6,563
N24 Waterford to Cahir 13,989

Average annual daily traffic of 6600 vehicles does not justify a Type 2 design (10~20k per year), let alone a Type 1. But, if you look at Waterford-Cahir, there's a high possibility that users are avoiding the substandard N24 west of Cahir and using an alternative route to Limerick, so traffic of 10k+ per year if there were a proper road seems reasonable.

steeler j · 18-10-2020 1:44pm

I wonder what is the number of vehicles that leave Waterford and arrive in Limerick

BelfastVanMan · 18-10-2020 2:43pm

KrisW1001 wrote: »

Waterford-Cork via N24 is a long detour (15% furhter) along a road that is much, much worse than the N25, and it would also funnel Waterford and Rosslare-originated traffic onto what is already the busiest arm of the Dunkettle interchange when it gets to Cork. Not a good idea.

N25 is also the Irish part of Euroroute E-30, so its status as the main route between Rosslare and Port of Cork is assured.

On the type of road, Type 1 has to be a mistake. The recent presentation (https://www.tii.ie/tii-library/conferences_and_seminars/nrc/nra-nrc-2019/12-Eoin-Doyle-Arup-Presentation.pdf , page 17) on 2+2 expressways gives traffic counts in 2018 for the two N24 sections up for improvement.

N24 Cahir to Limerick Junction 6,563
N24 Waterford to Cahir 13,989

Average annual daily traffic of 6600 vehicles does not justify a Type 2 design (10~20k per year), let alone a Type 1. But, if you look at Waterford-Cahir, there's a high possibility that users are avoiding the substandard N24 west of Cahir and using an alternative route to Limerick, so traffic of 10k+ per year if there were a proper road seems reasonable.

Futureproofing?
If the M20 (Whenever that comes) is closed for whatever reason, then M8/M24 would make a good alternative route, while doing it's own job of being the M24.
Probably not reason enough on it's own, but hey; a bit of Futureproofing is maybe just what we need for once.

KrisW1001 · 18-10-2020 5:33pm

BelfastVanMan wrote: »

Futureproofing?
If the M20 (Whenever that comes) is closed for whatever reason, then M8/M24 would make a good alternative route, while doing it's own job of being the M24.
Probably not reason enough on it's own, but hey; a bit of Futureproofing is maybe just what we need for once.

I don't think you know this road, somehow. A 2+2 is already a huge amount of future-proofing for this route overall, and for this section in particular.

Here's the latest data on traffic on the national road network:
https://www.tii.ie/tii-library/strategic-planning/tii-road-network-indicators/TII-National-Roads-Network-Indicators-2018.pdf

Page 9 shows the AADT counts for each stretch of primary and secondary road. You can see there that the only part of N24 that gets over 10,000 vehicles a day is the stretch between Carrick-on-Suir, Clonmel and Cahir.

A 2+2 is good for 20,000 vehicles a day, and that upper limit can be increased by changing junction designs (longer slip-roads, elimination of roundabouts). Type 1 with two lanes each way has a capacity of 38,000 vehicles per day, but costs about half as much again to build, and has a larger land-take.

Currently, traffic on this section of N24 is at just 6,000 a day, so today's figure could triple, and a 2+2 would still have enough capacity to deal with it.

Below the motorway tier, we still have a road network of sub-standard single-carriageway rural roads - the problem people face on these roads aren't to do with high volume of traffic, but the extremely low capacity of the existing roads. Upgrading these to 2+2 will fix the problem for decades. It will also draw some medium-distance traffic back off the motorway network.

BelfastVanMan · 18-10-2020 6:29pm

KrisW1001 wrote: »

I don't think you know this road, somehow. A 2+2 is already a huge amount of future-proofing for this route overall, and for this section in particular.

Here's the latest data on traffic on the national road network:
https://www.tii.ie/tii-library/strategic-planning/tii-road-network-indicators/TII-National-Roads-Network-Indicators-2018.pdf

Page 9 shows the AADT counts for each stretch of primary and secondary road. You can see there that the only part of N24 that gets over 10,000 vehicles a day is the stretch between Carrick-on-Suir, Clonmel and Cahir.

A 2+2 is good for 20,000 vehicles a day, and that upper limit can be increased by changing junction designs (longer slip-roads, elimination of roundabouts). Type 1 with two lanes each way has a capacity of 38,000 vehicles per day, but costs about half as much again to build, and has a larger land-take.

Currently, traffic on this section of N24 is at just 6,000 a day, so today's figure could triple, and a 2+2 would still have enough capacity to deal with it.

Below the motorway tier, we still have a road network of sub-standard single-carriageway rural roads - the problem people face on these roads aren't to do with high volume of traffic, but the extremely low capacity of the existing roads. Upgrading these to 2+2 will fix the problem for decades. It will also draw some medium-distance traffic back off the motorway network.

I drove it 3 times a week, from Ballysimon to Waterford for 5 years until very recently.

However, I take many of your points, there.

Pete_Cavan · 18-10-2020 6:46pm

KrisW1001 wrote: »

Waterford-Cork via N24 is a long detour (15% furhter) along a road that is much, much worse than the N25, and it would also funnel Waterford and Rosslare-originated traffic onto what is already the busiest arm of the Dunkettle interchange when it gets to Cork. Not a good idea.

N25 is also the Irish part of Euroroute E-30, so its status as the main route between Rosslare and Port of Cork is assured.

The point is is that if the N24 is 2+2 or even motorway, it would be a much higher quality route to take than N25. The majority being single carriageway, lack of movement on Castlematyr/Killeagh bypasses and the proliferation of roundabouts at Dungarvan with none of these to be addressed before the N24 would mean the N24 would become an attractive route; constant overtaking opportunity, no towns to pass through, etc. I don't think Dunkettle is an issue here, very little if any traffic originating from Waterford would be hitting it at peak time anyway.

I don't see why E30 couldn't be changed, in fact if a higher quality alternative route becomes available doing so would make sense. It would also link Rosslare with Foynes port. In the context of cross continental routes, the extra distance means nothing.

The traffic levels certainly call into question the need for motorway but it seems that is what TII are planning. As I said, if a level of Waterford - Cork traffic is added it may help justify it and 2+2 if not.

Chris_5339762 · 18-10-2020 8:10pm

All that said, if the N24 is FULL MOTORWAY and we're still left toddling around Dungarvans seven roundabouts, or we're stuck back to the lake waiting to get through Castlemartyr with no end in sight, it would be a disgrace.

marno21 · 21-10-2020 10:45pm

Website launched at https://n24cahirlimerick.ie/

Route options in Q2 2021 as previously mentioned.

davidk1394 · 22-10-2020 8:27am

The M24 is going to be passing thorough my farm. I'm south of Cahir and I can't see it going ahead for a number of years.

BelfastVanMan · 22-10-2020 8:32am

davidk1394 wrote: »

The M24 is going to be passing thorough my farm. I'm south of Cahir and I can't see it going ahead for a number of years.

The route hasn't been selected yet.

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

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