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

The first thing is that at present costings it shoud not costs 3 billion or even half it. It's a critical piece of infrastructure. In its present state due to accidents, crashes, time lose, economic loss to businesses it is probably costing the economy over 100 million a year.

In considering uneconomic projects, Colm McCarthy made a good point about the proposed North side and Airport metro. It costed at 10 billion. At present in consultant and other reports it has cost 240 million. It will cost double that taking it to the planning/ project viability stage over the he next 2-3 years.

His opinion is that there is no economic case for it at that cost.but because of the uproar it will not be shelved...but it will never be build in his opinion. If that 750 million was spend on bus infrastructure in Dublin how much better value would it be.

It's the same with the Limerick- Cork rail proposal it makes no economic sense. Rail projects in low density situation which even Dublin is are not good ways of spending money

https://m.independent.ie/opinion/comment/were-there-no-adults-in-the-room-when-they-drew-up-the-national-development-plan-40933253.html

Note that it’s the preferred option (or presumably mix of options) as opposed to preferred route that is due in March.

Well considering that we have three Green parties in Government, rather than just one (which was therefore supposed to have one-seventh of the influence) with the way both parties sold their souls to get into power for one more go of it, I'm not getting my hopes up.

The Nimby groups are much, much worse than they were and the judicial review line is far more of a sword than it used to be.

Don't forget, the M9/8/7/6/1 were all built without MASSIVE Nimby problems. Only the M3 and the Slane Bypass really got hit with issues (as well as the original Galway bypass). Nowadays pretty much every scheme gets bogged down.

Why wait? Either we get the Cork to Limerick M20 that we have been promised for years, or it is effectively canned by the Green Minister for Transport to comply with newly-introduced Green restrictions on road investments which the Greens demanded as a condition (among others) of going into coalition.

If it's the former, we get a pleasant surprise in March and a sense of relief that someone somewhere is still capable of making sensible decisions on infrastructure investment, and if it's the latter we will have gotten a head start on the justified complaints.

It is. The traffic figures speak for themselves.

Actually, there’s a possibility that the whole thing will be Type 1 DC, but that it will be the middle section, not the ends, that ends up under motorway restrictions if there’s a split. There’s lots of reasons not to have motorway regulations on a road with close-spaced junctions carrying a lot of commuter traffic. (See also N7, N25)

“It’s that simple”? No, it isn’t.

Before I start, I’ll say that I personally think the best approach is a Type 1 DC (what most people would call a “motorway”) for the whole length of the scheme, but that’s only for reasons of consistency; and I would expect the Cork end to be on green signs, not blue, because that’s what Cork County has done with all their other major approach roads.

On traffic numbers, however, there’s not a lot of justification for that position.

For example, now that Adare will be served by the new N69/M21 project, there is no traffic justification for any of the new-build N20 in Limerick to be a motorway (the already-built M20 serves Patrickswell). The original M20 plans had N20 here serving as part of a southern bypass of Adare, which would have produced enough traffic to justify a Type 1 DC. With Adare using M21 instead, you’ve got a road that serves only Croom and the very sparsely populated southern part of County Limerick - maybe 15,000 vehicles a day at the very most.

In this part of Limerick/Cork there is not a whole lot of diversionary travel - bad as N20 is, there really isn’t any better route than the current one (look at a map that shows mountains), so current traffic levels are pretty close to actual demand for North-South travel in this part of the counties.

A 2+2 from the M20/M21 interchange all the way to Mallow would be well within capacity (pre-pandemic peak traffic levels are around 11,000 - less than half the capacity of a 2+2), and it would be considerably cheaper to build than a motorway.

If I was responsible for getting value from the transport budget, I would seriously consider the 2+2 section, as that would allow me to use the savings for projects elsewhere on the network, and by doing that I could move forward other projects in Cork and Limerick. (Upgrading N71 from Bandon to Cork, or N24 Limerick Junction to Limerick, for instance).

Traffic numbers on the N20 are not reflective of the true figure of potential motorists driving this route as many Cork->Limerick drivers do not use the route at all. Instead, they use the M8 and R513. Look at the 2019 figures between the two Mitchelstown junctions (TMU M08 105.0 S & TMU M08 100.0 S) and you see that almost six thousand cars join/leave the motorway at the junction. Put that with anecodatal evidence reported on here, and from people I know, who never use the N20 simply because it's too slow, awkward and unsafe.

Furthermore, there is induced demand - traffic is attracted to better roads. A perfect example of this is the M17 motorway. It did not do one part of what its builders hoped it would do and take (the bulk of) traffic off the N17 for Galway. Instead, what it did do, is re-route a whole lot of Mayo->Dublin traffic down this route. Which is great news for all the back roads in Mayo that people were taking previously. Similarly, a tradesman I know in North Galway took a job in Limerick for a few months - he told me that he would never have considered it had the motorway not been built.

The same applies for the M20. Its construction will allow for more possibilities for people. Consider someone from Buttevant who has been offered a job in Raheen but is thinking of not taking it because they can't afford to rent in Limerick. With the M20, that becomes a reality for them. A safe, reliable journey into the outskirts of Limerick.

I would not normally be in favour of an absolutist, all-or-nothing approach to things, but in the case of the M20, it applies. In fact for me, it's simpler - it's not M20 or nothing. It's M20 or M20. Patrickswell to Blarney is only 80km - not 800. My concession to gradualism for me would be to do the Croom bypass upgrade last, since it's a pretty good road. Leaving Banoge to Blarney, a distance of 70km. And the highest priority is the dangerous 40km between Banoge and Mallow.

Let's not do an Ireland of the 1970s and half-ass this job now, like the 2+1 sections on the existing road. Build it once and build it right.

@cjpm - Cyclists are not permitted to use the vehicle carriageways of a 2+2 dual-carriageway, but the 2+2 road-type requires that a parallel cycleway must be provided. Private accesses are forbidden on 2+2 roads.

Agricultural machinery will end up on the road regardless. All modern tractors can reach the minimum speed required to use a motorway.

@serfboard Look at a relief map. The Galty mountains means there no other route but N20 between North Cork and South Limerick. Traffic leaving at Mitchelstown is not heading back towards N20 - at peak, 3,000 AADT on N73 between Mitchelstown and N20. Traffic on M8 and N24 does not drop either side of Cahir. Very, very few people are using M8 as a replacement for N20.

The difference between a type 1 DC and a 2+2 for your imaginary commuter is not really that significant. That trip from Buttevant to Raheen means driving on 40 km of road that is yet to be built. At a steady 100 km/h on a 2+2 that will take 24 minutes, at 120km/h it’s 20 minutes. There will be little to no congestion on either road type until the N21/M20 interchange.

Again, though, my preference is for Type 1 DC all the way through, but there are arguments for a 2+2 that are not just “doing it on the cheap”.

But it is.

A lot of traffic from North West Cork avoid the N20 too. I personally know a few people who detest the Cork Mallow section.

@cjpm I have been in favour of an M20 being built since the first round of interurban dual-carriageways were upgraded to motorways in the early 2000s. M20 is an appalling road, with numerous bottlenecks and unsafe sections, and it needs a new alignment purely on safety grounds.

In both my posts above, I said that I would prefer a Type 1 DC all the way through (Type 1 DC and “motorway” are the same thing in engineering terms). The use of a 2+2 for the low-traffic section in the middle is not my preferred option, but it is one I would be happy with: the very low traffic section from north of Mallow to Croom, is, and will continue to be, well within the limits of a 2+2, and 2+2 solves the most important issue here, which is driver safety.

Also, 2+2 roads have attracted less objections than anything labelled as a “motorway”, which can be useful given the lengths to which some people are prepared to go just to stop motorways.

What would not be acceptable is 2+2 all the way to Cork, as the southern end of N20 is a major commuter corridor, and traffic volumes exceed what a 2+2 can carry. I don’t like that so much of the traffic here is car commuters, but even if you got all of those drivers onto public transport, you’d still need Type 1 DC for the commercial traffic in and out of Cork here. (The M20 approach to Limerick is already a motorway).

Limerick and Waterford have motorway virtually all the way I to the city. There is no reason motorway could not be carried right up to the existing DC at Blarney.

All for a different thread, but the myth of the "hard pressed motorist" is way outside of the reasons to build the M20. The fictional "hard pressed motorist" is near enough to the worst possible reason to justify the M20

We spend enormous sums of money on ensuring that inefficient single-person vehicles can go wherever they want, to the detriment to other modes. I would say that motorists are paying nowhere near enough for that privilege. They're likely not contributing as much to the exchequer as they receive. Motoring remains the cheapest, easiest, most convenient form of transport available in Ireland. We desperately need to make other modes easier, more convenient and cheaper than motoring.

I say this as a motorist: don't go down that proverbial road!

I'm not against the M20 whatsoever, so you don't need to take issue with that.

I'm saying that justifying it by saying "motorists pay for so much" is not a good way to go. Motor related revenues are around 6.2bn. Emissions fines are something like 0.5bn, the roads budget is around 2.5-3bn, and then you add in cost of deaths, health related costs related to traffic, emissions, noise, education, etc. Cost justifications aren't a good route forward, to justify the M20.

M20 has plenty justification without needing to rely on costs. Talk about deaths, cost to the economy, costs to health by way of traffic hazard etc. These all are good justifications for an M20 but costs to end users aren't a good sell. Motoring is still by far the preferred transport mode in the country. Costs are not a deterrent right now.

Has there been any discussion on tolls? With proposed upcoming congestion charges, would the congestion charge negate the need for a Southern toll? Or would two charges apply? Possibly nobody knows this yet....