M20 - Cork to Limerick [preferred route chosen; in design - phase 3]

hans aus dtschl

steeler j wrote: »

so people in mallow never travel to Limerick or people in croom travel to Cork

Their point/logic is fuzzy but I believe they're simply saying "most of the traffic on the N20 isn't end-to-end".

That's correct: I think the vast majority of traffic on the route is not end-to-end, but that simply means that the N20 will need to be upgraded going by traffic numbers, regardless of any alternate routes.

Whichever way you slice the pie, the N20 needs an upgrade. The only justifications for alternate routes are on their own merits, not as an alternative to the M20.

Which is unfortunate, because it looks like providing the M20 is political kryptonite.

steeler j

hans aus dtschl wrote: »

Their point/logic is fuzzy but I believe they're simply saying "most of the traffic on the N20 isn't end-to-end".

That's correct: I think the vast majority of traffic on the route is not end-to-end, but that simply means that the N20 will need to be upgraded going by traffic numbers, regardless of any alternate routes.

true but wouldn't a motorway be better for people traveling between croom and mallow or mallow and blarney

Isambard

steeler j wrote: »

true but wouldn't a motorway be better for people traveling between croom and mallow or mallow and blarney

and it's not just the towns actually on the N20. My home is 20 minutes from the N20 and 60 from any Motorway, and there's plenty of other towns even further West and South that badly need the N20 upgrading.

neddynasty

It really annoys me when I hear people pushing for an M20 or an M24. Why does it have to just be one? Why aren't we pushing for both? The obvious answer is finances but the public money wasted in this country over the last 20 years is scandalous, from giveaway budgets to the children's hospital to the banking crisis. We should be demanding both roads and make the government find a way to fund it.

hans aus dtschl

neddynasty wrote: »

It really annoys me when I hear people pushing for an M20 or an M24. Why does it have to just be one? Why aren't we pushing for both? The obvious answer is finances but the public money wasted in this country over the last 20 years is scandalous, from giveaway budgets to the children's hospital to the banking crisis. We should be demanding both roads and make the government find a way to fund it.

That's all well and good, but is an M24 badly needed?
I have no idea, it's not a route I travel often. TII documentation from 2016 states that it was 5-10k AADT per day. I know AADT is not the entire justification for an upgrade, but if it were, then the N20, N22, N25, part of the N71 etc would all be higher priority than the N24. (That's just the ones in Cork).

Agreed that it shouldn't be "just one" but if it was "just X" then it would still be a long time before the N24 would make the cut, on AADT figures.

https://www.tii.ie/tii-library/strategic-planning/nra-road-network-indicators/TII-National-Road-Network-Indicators-2016.pdf

Edit, looking further down the same document it looks like there's justification for an upgrade of the section from Cahir to Tipp Town alright, but that's about all.

niloc1951

Isambard wrote: »

I think it may not have been your intention, but you did say that Mallow Buttevant and Charleville don't warrant a Motorway, but Clonmel and Carrick on Suir do.

#
#
No, I didn't say that. I said a direct route from Galway/Limerick to Waterford and on to Rosslare could serve Clonmel and Carrick on Suir as a by-product. You could also add Tipperary town and Cahir to that.

As has been said, there are a lot of people, including myself who currently choose the M8/R513/N24 route, the distance is pretty much the same and it has a quicker and more predictable travel time.

Has TII done a traffic survey on the N20, does anyone know what is the percentage of through intercity traffic versus local inter town traffic?

hans aus dtschl

niloc1951 wrote: »

Has TII done a traffic survey on the N20, does anyone know what is the percentage of through intercity traffic versus local inter town traffic?

Yeah this work was done. I think it's even displayed earlier on in this thread tbh. I believe the intercity portion was very low. Likely in part because of people like you and I using alternate routes to avoid the N20.

hans aus dtschl

KCAccidental wrote: »

that was taken from the feasibility study for the M20 a few years back

Quote:
The Traffic section of the Pre-Feasibility report included the following :

o The study made use of existing traffic data only. Existing data compiled comprised
Automatic Traffic Count Data from NRA, Roadside Interview (RSI) Survey data, Manual
Classified Counts and NRA estimated counts along the N20 and N8.

o RSI data was used to construct trip matrices to summarise traffic demand on the N20,
N72, N8 and N24 routes. Data was coded to a system of 21 zones that allows the
capture of movements to and from key settlements within the study area.

o From this data the study built a likelihood matrix for each corridor option. If a trip is likely
to use the corridor a digit „1‟ is placed, and the same with a figure „0‟ in the case of not
using this corridor. The sum of results from this likelihood matrix is applied to the total
volumes for every pair to get the forecast of use of every corridor. In the case that both
options are equally likely for a particular trip, a figure „1‟ is placed in both matrices,
indicating that it could be captured by both options.

o Traffic volumes along the N20 are shown in the study. Traffic varies from near 25,000
vehicles AADT near Cork, around 17,000 between Cork and Mallow, near 20,000 in
Mallow at the N72 intersection, 10,000 to 11,000 between Mallow and Croom, and near
15,000 between Croom and Limerick. Around Limerick volumes are about 25,000. HCV
traffic remains relatively constant along the length of the corridor, with a percentage that
varies between 7 & 14%; the highest (14%) is between Cork and Mallow.

This study concludes that for long distance traffic either corridor option could be used based on
similar route distances. This is not the same for short and medium distance traffic movements. In
this case the Eastern Corridor would not attract significant volumes of traffic, as it does not pass
through any of the key locations of population, industry or employment, such as Mallow,
Charleville, Buttevant, Croom, Patrickswell and Blarney.

The study also showed that only a relatively small proportion of the existing traffic on the N20 is
travelling the full distance between Cork and Limerick or beyond. The analysis done on the N24
also suggested that almost none of this traffic travels beyond Tipperary.

To summarise the potential attraction for vehicles from the N20, the study provides a table
which indicates that only about 2,100 vehicles would be transferred to the Eastern
Corridor, and concludes that the majority of traffic using the existing N20 (Western
Corridor) will still use it or an improved version.

The additional information gathered as part of traffic study for the M20 scheme reinforces the
recommendations of the Pre-Feasibility Study in the following aspects:

- Strategic “Long distance” trips along the N20 route are between 20 to 30% of total flows.
Therefore remaining flows consisting of a minimum of around 8,000 vehicles and a maximum of
14,000 vehicles that would not be captured by a potential Eastern Corridor.

- Local and Commuter trips are very significant along the N20 route. In particular, traffic from
Mallow to Cork is very important, reaching volumes above 8,000 vehicles per day (adding flows
not only between these two main cities but traffic that is generated by intermediate zones inside
that section). This volume would not be captured by the Eastern Corridor.

- The Western Corridor option still provides for the strategic long distance trips and provides a
necessary upgrade to the existing N20 route to cater for significant traffic flows into the future.
We conclude that the recommendations of the Pre-Feasibility Report were correct and the Western
Corridor should be pursued as the route for the Atlantic Corridor.
that was taken from the feasibility study for the M20 a few years back

link here (pdf file so beware) http://www.corkrdo.ie/files/M20/FTG_Pre-feasability-Study/Pre-Feasibility%20Report%20Update%20FINAL%20%2003122008.pdf

Thanks to KCAccidental from a few years ago.

Mc Love

If there was choice between going on the N20 or the M8 route, I'd still take the N20 route, I mean have you been on the Dunkettle?

steeler j

hans aus dtschl wrote: »

That's all well and good, but is an M24 badly needed?
I have no idea, it's not a route I travel often. TII documentation from 2016 states that it was 5-10k AADT per day. I know AADT is not the entire justification for an upgrade, but if it were, then the N20, N22, N25, part of the N71 etc would all be higher priority than the N24. (That's just the ones in Cork).

Agreed that it shouldn't be "just one" but if it was "just X" then it would still be a long time before the N24 would make the cut, on AADT figures.

https://www.tii.ie/tii-library/strategic-planning/nra-road-network-indicators/TII-National-Road-Network-Indicators-2016.pdf

Edit, looking further down the same document it looks like there's justification for an upgrade of the section from Cahir to Tipp Town alright, but that's about all.

yes it is needed , Dromkeen to Waterford some terrible parts but all the roads in Munster need an upgrade the n20 ,n21,n22 ,n24 ,n25 ,n28 and n71 ,2 or 3 of these should already be done

Isambard

steeler j wrote: »

yes it is needed , Dromkeen to Waterford some terrible parts but all the roads in Munster need an upgrade the n20 ,n21,n22 ,n24 ,n25 ,n28 and n71 ,2 or 3 of these should already be done

add to that the N72 and N73 which hopefully will benefit from the M20 being built. These are truly dreadful roads.

steeler j

Isambard wrote: »

add to that the N72 and N73 which hopefully will benefit from the M20 being built. These are truly dreadful roads.

the list is endless

niloc1951

Mc Love wrote: »

If there was choice between going on the N20 or the M8 route, I'd still take the N20 route, I mean have you been on the Dunkettle?

Ok, Dunkettle is bad at present due to no future proofing at the time of build. However, with a new proper freeflow intersection due to be opened in 2022 it's a bit irrelevant factoring it's present maladies into projects for completion post 2022

Isambard

niloc1951 wrote: »

#
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No, I didn't say that. I said a direct route from Galway/Limerick to Waterford and on to Rosslare could serve Clonmel and Carrick on Suir as a by-product. You could also add Tipperary town and Cahir to that.

As has been said, there are a lot of people, including myself who currently choose the M8/R513/N24 route, the distance is pretty much the same and it has a quicker and more predictable travel time.

Has TII done a traffic survey on the N20, does anyone know what is the percentage of through intercity traffic versus local inter town traffic?

But you don't think Charleville, Buttevant and Mallow could be served as a byproduct of the M20?

AugustusMinimus

niloc1951 wrote: »

Ok, Dunkettle is bad at present due to no future proofing at the time of build. However, with a new proper freeflow intersection due to be opened in 2022 it's a bit irrelevant factoring it's present maladies into projects for completion post 2022

After fixing the junction why go and dump a load more unnecessary traffic. Madness.

highwaymaniac

AugustusMinimus wrote: »

After fixing the junction why go and dump a load more unnecessary traffic. Madness.

Totally agree, westbound on N40 still will be an issue post Dunkettle because of crashes
eg Bloomfiledd westbound merge. Is road network redundancy and journey time really reliability an alien concept?!! Have no lessons been learnt from merging the M8 and M9 into the M7.

highwaymaniac

Also the alignment and gradient of the last few kms of the M8 (ie the 100 km/hr Glanmire bypass) are substandard and will have an effect on capacity at higher flows, due to some vehicles slowing down and mixed with higher speed vehicles braking late etc.

steeler j

any major design elements that may cause delays in the process

marno21

Senior Cork County engineer doubts there will be a change to Cork-Limerick route

https://www.irishexaminer.com/breakingnews/ireland/senior-engineer-doubts-there-will-be-change-to-cork-limerick-route-918069.html

riddlinrussell

marno21 wrote: »

Senior Cork County engineer doubts there will be a change to Cork-Limerick route

https://www.irishexaminer.com/breakingnews/ireland/senior-engineer-doubts-there-will-be-change-to-cork-limerick-route-918069.html

What utter rubbish, if they have to make no revisions then its 15 million well spent because they'd never have gotten it past the planning stage if it wasn't reassessed for environmental impact and new road standards at a minimum?

Even if its just a rubber stamping exercise all that means is that the rest of the planning should go quicker because they can argue minimal change from last time was needed?

Isambard

i think he's only saying the route is likely to be the same, not the plans will be re-used.

marno21

Isambard wrote: »

i think he's only saying the route is likely to be the same, not the plans will be re-used.

This. If the 2008 route was the best route in 2008 there's a strong chance it'll be the best route in 2019 too.

highwaymaniac

marno21 wrote: »

This. If the 2008 route was the best route in 2008 there's a strong chance it'll be the best route in 2019 too.

I think they should go offline from Blarney, construction of online section to south of Mallow would be a nightmare. Not sure why this was favoured last time out.

AugustusMinimus

highwaymaniac wrote: »

I think they should go offline from Blarney, construction of online section to south of Mallow would be a nightmare. Not sure why this was favoured last time out.

Cost savings I suspect. Most of that section of road was only opened in 1990 or so.

highwaymaniac

AugustusMinimus wrote: »

Cost savings I suspect. Most of that section of road was only opened in 1990 or so.

On paper perhaps, but slower construction and more landowners to deal with, tricky enough terrain, noise considerations, I'd say a bit of a false economy.

marno21

Rathduff-Blarney online is a no brainer. The terrain around there, the railway would make another alignment difficult. In addition to the existing road being 15m wide and not far off motorway width.

There will be CPO challenges around Rathduff and works to be done with tying in local roads but an offline alignment would be needless expense.

highwaymaniac

marno21 wrote: »

Rathduff-Blarney online is a no brainer. The terrain around there, the railway would make another alignment difficult. In addition to the existing road being 15m wide and not far off motorway width.

There will be CPO challenges around Rathduff and works to be done with tying in local roads but an offline alignment would be needless expense.

I think they will take a risk adverse approach, I suspect that they will be very cautious about Rathduff given objections from Buttevant folk last time out.

I still think the overall costs of online v offline are pretty close.

Isambard

very few people live in Rathduff. I can't see them objecting to removal of that awful junction which must be a huge worry to anyone using it daily.

Online from there to Blarney is as Marno says a no-brainer, but I dread the traffic chaos that will ensue. Looks like I'll be using the rat runs for a couple of years!

niloc1951

Isambard wrote: »

very few people live in Rathduff. ...............

True, but add in Grenagh 1.5km to the west and that makes a difference.
In fact the old Rathduff Station is part of the longterm plan by Irish Rail to run the commuter from Midleton directly on to Mallow serving existing stations plus re-opened Glanmire Blackpool, Blarney, Rathduff and Mourabbey.
I suppose futureproofing was never a strongpoint with The NRA/TII notwithstand a projected population increas of over 30% on the next 30 years.

Isambard

Grenagh is the other side of Rathduff to the previous proposed line so hardly come into it.