N8/N25/N40 - Dunkettle Interchange [open to traffic]

cork_south

https://www.boards.ie/discussion/comment/121412541#Comment_121412541

Try hitting the Glanmire roundabout in the mornings and doing a U turn to access the tunnel from the M8S. It's much quicker and less stressful

That coned off lane is around is around 500m in length and is ready to be opened for over 4 weeks.

I don't really understand why they won't open it, or even a stretch of it. It's causing tailbacks out onto the N25W affecting traffic heading to the city and could cause an accident.

Markcheese

If they changed the road markings,so each lane merges and had serious signage about merging in turn , it MIGHT work , its a bit of a pinch point, traffic accelerates away from the merge -

niloc1951

With wesrbound traffic for the N40 travelling at 120kmh or even 80kmh arriving at 60kmh pinch point once the volume per minute reaches a certain rate a queue will ALWAYS form, it's simply physics. How the lanes merge isn't going to effect the exit time from the pinch point, except for queue jumpers and their time saved is added to the others.

The only way I can see to reduce the queueing is zipper merging at 60 or 80 kmh but that isn't going to happen in a safe manner with the way drivers habitually tailgate, at even 120kmh.

cork_south

Traffic from Tivoli roundabout backing all the way up into the tunnel Northbound now.

Glanmirelad

vari signs.jpg

I wonder what effect the variable speed displays will have on the queuing at peak times , and whether they will even be adhered to or enforced by the traffic police .

Chris_5339762

None whatsoever, because no-one obeys the limits as they are.

p_haugh

They're also only advisory as of now. The legisation was passed in June (Road Traffic and Roads Act 2023), but the commencement order that will make them enforceable hasnt been made yet! And even then, it sounds like only the M50 will be enforced initially before a wider rollout.

niloc1951

The physics of the above can't be denied or modified. No matter what is done to the upper (queueing) section the throughput of the pinch point determines the speed of the flow and how fast the upper section empties.

Chris_5339762

And if they added another bore to the tunnel, then the merge will have to happen there instead, unless you widen the entire south ring right to the Kinsale Road junction. And that brings in the problem of the Douglas Viaduct.

hans aus dtschl

I don't think any more N40 South upgrades are a good idea now, including the tunnel itself. It must be N40 North next surely.

All along the N40 South the investment needs to be in sustainable transport alternatives instead IMO. Any additional tunnel bore would be for sustainable transport. And even then, it's just not going to be happening, the next river crossing will be the bridge by Tivoli.

cork_south

https://www.boards.ie/discussion/comment/121432321#Comment_121432321

The Bloomfield interchange on N40 will surely require some sort of upgrade I would have thought.

It's choked right now, it will be a hell of a lot worse when the tunnel works & M28 are fully completed.

niloc1951

https://www.boards.ie/discussion/comment/121432334#Comment_121432334

Exactly, the current pinch-point, which is Carrs Hill, will be gone so the free-flowing (faster moving) traffic on the M28 heading to the N40 Jct.9 westbound will only serve to exacerbate the current queueing at Jct9 and the Doughas flyover.

A third westbound lane on the Douglas flyover, connecting the merging lane at Jct9 with the exiting lane at Jct6 should be the last piece of the jigsaw.

I don't see westbound traffic on the N25 heading to the western and southwestern suburbs of the city opting for the circuitous route of the proposed N40 North.

hans aus dtschl

Yep, we've built up a huge demand of car-based commuting using the N40 and we've no easy way out of it.

But building more capacity for car commuting through what is now the city it isn't a solution either. 60-70% of people are commuting by car right now. So any new capacity will become congested again in short order,. The problem is that both long-distance and short distance commuter journeys are being combined on the N40. The solutions are Southern Distributor, Northern Distributor and Northern Bypass and a very large dose of sustainable transport infrastructure.

The biggest reason not to "more N40 south" our way forward is because it's now a single enormous point of failure for the city's transport system.

I've no major issue with a third Westbound lane on the Douglas flyover, but it's only going to have a small net benefit unfortunately. One crash there and the whole city comes to a halt. We need alternatives now quite urgently.

FishOnABike

The simplest solution is to reduce traffic. Strengthen remote work / work from home rights from a right to request it to requiring the employer to prove why a job can't be done remotely and traffic levels could drop significantly.

I could work almost 100% remotely but policy means I need to be in the office two or three days per week. I could save those two or three days per week commuting if I could work remotely, with the exception of when a physical presence was essential.

niloc1951

If working from home was to become widespread, why the need for the projected increased need of public transport.

And, will we see any significant drop in private car use as we transition from fossil fuel vehicles to renewable energy electric vehicles, particularly when population growth is factored in.

How valid is the assumption that less not more roads is the future.

AugustusMinimus

https://www.boards.ie/discussion/comment/121433543#Comment_121433543

Everyone working at home would be terrible for the economy and quite frankly sounds like a dystopian nightmare.

cork_south

https://www.boards.ie/discussion/comment/121436058#Comment_121436058

To me the dystopian nightmare is spending up to 2 hours a day away from my family commuting via the tunnel to do a job I was easily able to do for 2 years fully WFH during covid.

Cookiemunster

The reality is very few people can actually work from home. People working in manufacturing, retail, construction, public facing public and civil servants many others have to and will continue to have to travel to work. That's the vast majority of the working public.

WFH is fine for those that can do it, but it won't do much for traffic volumes.

prunudo

Ah WFH, the utopia idea that those that it works well for, smugglingly tell the rest of us that is the best thing in the world and we all need to do it. Without accepting it doesn't suit a large portion of the workforce.

cork_south

https://www.boards.ie/discussion/comment/121436384#Comment_121436384

Ah Mandatory Work From Office - the utopia idea that those that it works well for, smugglingly tell the rest of us that is the best thing in the world and we all need to do it.

Without accepting it doesn't suit a large portion of the workforce.

Chris_5339762

Someone went in the back of me several months ago causing one of those miserable days of long tailbacks along the south ring.

The last three mornings I have noticed near misses, witheringly poor driving and brutal merging from Mahon all the way to Douglas. No wonder there are so many accidents. We all know this, but what can actually be done about it? You could put 100 garda cars driving along the south ring and it wouldn't make a difference.

Variable speed limits (which would help with merging issues at the M28) would make a huge difference but would be universally ignored, like the Dunkettle roadwork speed limits. I swear that guy was so close to my rear bumper this morning he was pretty much in the boot.

hans aus dtschl

https://www.boards.ie/discussion/comment/121434137#Comment_121434137

I don't think it's a question of "less rather than more roads" but a slightly more nuanced "more efficient use of transport infrastructure". It's not just about the environment, it's about wasted time and resources.

Someone living in the countryside near Ballymacoda is going to be difficult to tempt onto more efficient modes of transport. But someone living in Douglas should have multiple transport options and should be heavily incentivised to do so. The only real way you can do that is by having a carrot and stick: make the efficient modes of transport way more attractive and make the car less attractive. You can't just ban people in Douglas from using their car, because some need the car.

Conversely, if we just add more capacity for cars around Douglas, then we'll get more cars around Douglas. You might marginally benefit the journey of the person from Ballymacoda, but realistically you're mostly just going to work against any mode-shift at Douglas.

And before someone says "what about buses, they need roads too", the N40 has absolutely no prioritisation for buses. Even the N27 has very little. So if I have a car and I'm deciding between a bus or car journey on the N40, N27, N8, N25 then at the moment the choice is very simple. And once you're in the car, it's very hard to get you out of the car.

TLDR: investment in car-oriented transport for city-area commuters is a false economy unless it's heavily out-balanced by other modes. Northern and Southern "distributor" roads are a realistic way forward. And bypasses are needed for the people who simply want to get past the city. And multi-mode transport hubs are needed all around the city. So it's not "no more roads" but rather "no more dual-purpose bypass-distributor roads in/near the city because we know they don't work".

Markcheese

https://www.boards.ie/discussion/comment/121434137#Comment_121434137

If we're depending on cars and we are more and more then electric cars are no change at all - an EV takes up the same space as a petrol car -

The only soloution is better public transport first , and no politican ever gets thanks for that ,

ColemanY2K

https://www.boards.ie/discussion/comment/121436966#Comment_121436966

Variable speed limits work in the UK because they are complimented with fixed speed cameras. One way to stop people ignoring the limit is to hit them in the pocket with fines, penalty points, driving bans and subsequently higher premiums as a result. The M1 in England has quite a few south of Leicester and notably the M6 north of Birmingham has a variable speed limit for about 60 miles. However drivers tend to hammer the accelerator as soon as vehicles leave the section of road with the variable speed limit.

Personally I firmly believe a variable speed limit should be mandatory on all motorways, dual carriageways and any main road which has a high fatality rate. Set cruise control and sit back.

Hibernicis

Dronehawk's latest. With the grass growing and the retreat of the construction equipment, it's starting to take on a "finished" appearance

https://www.youtube.com/watch?v=YMHb07ZODp8

Padraig Mor

Permanent 'queueing traffic' signs went up at the weekend on the approach to the tunnel from the East - if that's not an admission of failure in the whole point of the upgrade before it even fully opens, I don't know what is.

Cookiemunster

But the upgrade isn't a failure. N25 East and West to the M8 is now free flow. Tunnel to M8 and N25 East and West is now free flow. Little Island to these points either is or will be free flow.

No upgrade can hide the fact that the tunnel itself is the issue, not the junction.

hans aus dtschl

https://www.boards.ie/discussion/comment/121457985#Comment_121457985

While that's absolutely true, I think very many people expected that the works would resolve the traffic issues.

I had been telling many people for a long time that this project isn't going to fix everything: the Tunnel is effectively at capacity.

cork_south

The project has fixed (will fix) many of the junctions but lumping additional traffic (Ibis slip) onto what was already an overloaded junction (N25W) has not helped N25 user's.

I'll continue to access the tunnel from N25W via the Tivoli roundabout at peak times unless there's a dramatic change in how traffic flows N25W to tunnel once the works are fully complete. In fact there should be even less traffic using Tivoli roundabout when N25W to M8N opens.