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

You might be surprised, but a significant number of people use the old youghal road (Glounthaune) when the N25 backs up. It never ever works out faster for them, but it's a lot of people's favourite rat-run!

Absolutely they do when the road is backed up but the majority will use the N25 and go through Little Island if traffic is backed up to there.

Seeing traffic backed up on the N25 past Cobh Cross will force many folks to rat run off the slips through Carrigtwohill and onto Glouthuane for sure.

I learn something new every day.

I misunderstood, I thought you meant this week! Yes the final design will be WAY better, once there's free-flow into the tunnel from the East.

The Ibis slip road was a problem anyway, to be honest. Traffic was backing up on Glashaboy Hill most mornings, and there was a lot of bad behaviour on the M8 Southbound merge, even leading to police monitoring it. It needed to be dealt with, regardless of the new Little Island West interchange.

I still reserve the right to point out the M8South traffic rat-running off the M8, to avoid the Little Island interchange towards the end of next year when the overall project is complete though! We will see that at Dunkettle Roundabout (Glanmire Village direction) and Riverstown Cross, if anywhere. And of course, hopefully I'm wrong!

Apologies, if this was discussed earlier.

Is the ibis slip due to reopen or is it gone for good.

Ibis slip is gone for good yep. The future plan for that traffic flow is very close to what's in place now. They will cross the newly-opened dumbell interchange (Little Island West) then begin to head towards the tunnel, merging with the N25 (Midleton) traffic heading either towards Tivoli or the Tunnel (2 distinct routes, from the newly-opened Interchange Westwards).

The M8N (Dublin) traffic will join them through that newly-opened dumbell interchange. They will meet at what is now the (currently unfinished) northern roundabout of the newly-opened interchange.

I hope all this makes sense.

TLDR: yes Ibis slip gone for good.

i think some of the delays we are currently seeing are just the beginning of much wider issue that is going to arise in multiple other locations in the city roads infrastructure once dunkettle is completed.

Take all the current ibis/little island/midleton traffic heading towards the tunnel and freeflow all that (along with all the m8 traffic) right down the funnel that is the bloomfield merge/douglas flyover and there will be issues. granted there is no traffic light but that merge is going to slow right down and inevitably cause tailbacks.

Similarly, freeflow all the traffic hitting the Glanmire roundabout & Little Island and there could be issues.

The pessimist in me feels the anything gained at dunkettle is probably just going to be shifted elsewhere with little overall gain in more general terms, yes you will get through dunkettle easier but you may just end up delayed further along on your journey.

Hopefully i'm wrong but i'm just not overly confident about it

It’ll drastically improve getting out of the city.

However it will put untold pressure on the Douglas flyover.

I actually think the Dunkettle Roundabout is the biggest issue. With it now being signalised, you could see traffic backing up from it onto the new interchange and clog it up.

The Douglas flyover will become the single worst bottleneck in the country when Dunkettle is done. I've said that before on this thread but I really hope I'm wrong.

Especially when the M28 gets done. Jamups in the morning will stretch from there to Dunkettle (if you look solely at the length of the jams at the moment and put them all there).

In the evenings it will be far better yes, but I still worry about the Dunkettle roundabout and traffic backing up onto the N40W to N25E slip from the new Little Island junction.

There are a few smaller bits coming through on the cycling side too, which will help. Some of these are in the near future and can take a couple of percent of users off the N40. And BusConnects, which is a long way off will take a few per cent more. Remember the big issue (and part of the solution) isn't the long-distance people (Youghal to Ballincollig, say) but the more typical commuter doing 5-10km. I know people who cycle for leisure but commute through the tunnel: getting them a comfortable route and facilitating them at the endpoint can get cars off the N40 for certain: distance or fitness isn't the problem for them it's the safety and the (dis)comfort.

I also know people doing 40km each-way through the tunnel daily. Those are the people who aren't going to easily find alternatives.

Edit: it's CMATS basically, let's be honest with each other. We need implementation of more of CMATS. And increasing N40 capacity isn't a part of that plan.

Backed up beyond Carrigtwohill this morning. They really need to do something fast. Unsustainable situation.

The issue on the N25 caused by the Ibis slip closure hasn't even been acknowledged on the Dunkettle app or on their related social media platforms.

I'd say this will be the norm going forward in the hope that upcoming road changes may help alleviate the problem.

I come that way twice a week and had become used to it being backed up a good bit....2 kms maybe?

Anyway, this week I flew through there, no traffic there but it seems to just have moved up to around Silversrings and the Lower Glanmire Road. Absolutely jammed and barely moved from there all along the quay into Penrose Wharf.

I have two more comments which will get me rained on!

1) I don't think they'll do anything with the worse N25W jamups. When they closed the left hand lane on the N40E coming out of the tunnel, it was done with promises that they'd reduce the scope of the works as soon as they could. Now, I know they have had problems with awful weather. But they haven't removed a single centimeter of works so far and they seem to just not care about the increased delays in the evening. They should manage jamups to the best of their ability, but so far they just haven't bothered it seems. The best we'll get is a cursory mention about increased queuing in the newsletters.

2) Is SCOOT actually doing anything? The sequence of the lights is the same at all times of the day, day or night. It doesn't use the sensors to dynamically change anything at low traffic conditions during the night in the way some crossroads do. And the length of any of the greens doesn't change either. It also hasn't dynamically adjusted anything now that the jams have moved to N25W and that M8S has no jams at all in the mornings. Nothing has changed. I have yet to see an iota of evidence that SCOOT is actually adjusting for anything and they've had several days now to gather data. Reduce the M8S green time slightly, increase the N25W green times. Simple. But I grant you the execution might be trickier.