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

Middle Man · 06-01-2018 2:44pm

marno21 wrote: »

Work has begun on the Dunkettle Interchange scheme, with clearance works now visible beside the old Ibis hotel.

TII say a contractor will be appointed "in the next few months" and "some work may start before the end of 2018".

http://www.irishexaminer.com/ireland/dunkettle-interchange-upgrade-begins-465384.html

Probably enabling works prior to the main construction phase.

hans aus dtschl · 18-01-2018 10:43am

Firstly, I'm no expert, but...
Given that the current interchange design was based on figures from 2010, which predicted AADT of 67k through the tunnel by around 2031....and we've now actually surpassed that....is there anything to be said for another few minutes thought about putting in a dedicated M8 (Dublin-Cork) route on this interchange.

I just can't see how the Glanmire-Tunnel, Dublin-Cork, Dublin-East, Tunnel-East and Little Island traffic can all go through the same short stretch and all cross over each other safely.

It just seems obvious to me that the design they're building won't work.

Again, I'm not an expert.

AugustusMinimus · 18-01-2018 12:00pm

hans aus dtschl wrote: »

Firstly, I'm no expert, but...
Given that the current interchange design was based on figures from 2010, which predicted AADT of 67k through the tunnel by around 2031....and we've now actually surpassed that....is there anything to be said for another few minutes thought about putting in a dedicated M8 (Dublin-Cork) route on this interchange.

I just can't see how the Glanmire-Tunnel, Dublin-Cork, Dublin-East, Tunnel-East and Little Island traffic can all go through the same short stretch and all cross over each other safely.

It just seems obvious to me that the design they're building won't work.

Again, I'm not an expert.

Off the top of my head, of the 12 primary movements on this junction, only one isn’t free flow which is as you say, M8 South to N8 Tivoli.

This movement will involve going through 2 roundabouts.

Given that this is only 1/12 of all main movements, I don’t personally think it will hugely affect traffic. I also believe this is the least trafficked of all main movements.

Even at peak hours, you don’t see a huge amounts of cars doing this move.

I personally think the junction is sufficient. The tunnel being only 2 lanes will be the bottleneck, not the junction.

marno21 · 18-01-2018 12:30pm

If there was only room for 11 movements free flow M8 -> N8 makes sense, as it comes to a stop about 2km further in anyway, whereas the rest flow into free flow dual carriageways.

Sean Sherlock made the excellent point on C103 yesterday that any notion of the motorway to Limerick going via Mitchelstown is out of the question as Dunkettle hasn't been designed with this flow in mind. Limerick traffic should use M40 North West quadrant if possible when built.

The main thing that needs to be in consideration with this upgrade is the effect on flow further on. The Lakeview roundabout in Midleton and Castlemartyr village are 2 areas in particular that need examining as they will be under pressure after this is done.

AugustusMinimus · 18-01-2018 12:56pm

marno21 wrote: »

If there was only room for 11 movements free flow M8 -> N8 makes sense, as it comes to a stop about 2km further in anyway, whereas the rest flow into free flow dual carriageways.

Sean Sherlock made the excellent point on C103 yesterday that any notion of the motorway to Limerick going via Mitchelstown is out of the question as Dunkettle hasn't been designed with this flow in mind. Limerick traffic should use M40 North West quadrant if possible when built.

The main thing that needs to be in consideration with this upgrade is the effect on flow further on. The Lakeview roundabout in Midleton and Castlemartyr village are 2 areas in particular that need examining as they will be under pressure after this is done.

Most pressing concern would be Dunkettle Roundabout in my mind.

May require a flyover. In addition, redrawing of road markings before the flyover for the North Ring Road.

Agreed on M20. Dunkettle should not have more traffic forced upon it.

hans aus dtschl · 18-01-2018 1:21pm

AugustusMinimus wrote: »

Off the top of my head, of the 12 primary movements on this junction, only one isn’t free flow which is as you say, M8 South to N8 Tivoli.

This movement will involve going through 2 roundabouts.

Given that this is only 1/12 of all main movements, I don’t personally think it will hugely affect traffic. I also believe this is the least trafficked of all main movements.

Even at peak hours, you don’t see a huge amounts of cars doing this move.

I personally think the junction is sufficient. The tunnel being only 2 lanes will be the bottleneck, not the junction.

That's a reasonable point.

I can tell you anecdotally (I've no numbers) that significant volumes now access the north and east of the city by exiting the M8 at Watergrasshill and using the R639/R616. They don't tend to exit at Glanmire any more as that's often gridlocked from R615 junction back to beyond L2973 from around 0715 to around 0830 or later.

Some (less) M8 traffic is also bypassing the interchange by using the Watergrasshill in order to head east.

I guess what I'm saying is that many intending users have simply given up on the junction.

I know that's neither here nor there but it may be worth bearing in mind when we talk about lack of demand as a justification.

hans aus dtschl · 18-01-2018 1:29pm

marno21 wrote: »

If there was only room for 11 movements free flow M8 -> N8 makes sense, as it comes to a stop about 2km further in anyway, whereas the rest flow into free flow dual carriageways.

This is sensible. My contention here is that this won't be the case for the M8-M25 slip. I believe that this will be a pinch point due to a backlog of traffic from the roundabout ahead.

Bacchus · 18-01-2018 1:52pm

marno21 wrote: »

The main thing that needs to be in consideration with this upgrade is the effect on flow further on. The Lakeview roundabout in Midleton and Castlemartyr village are 2 areas in particular that need examining as they will be under pressure after this is done.

^
This.

Delays through both are reasonable at the moment (2 minutes at Lakeview, 5 minutes as Castlemartyr... when I am typically going through in evening) but if there's an unbroken flow of traffic coming from the South ring and Dunkettle Roundabout I can easily see these becoming even greater bottlenecks. Not to mention how much the queue of traffic taking the first exit for Middleton will back up (due to traffic light system)... likely spilling onto the dual carriageway.

Jippo · 31-01-2018 7:33pm

Drax wrote: »

Excellent news indeed... expect it in around 10 years. :pac:

You weren't conservative enough.

DerMutt · 04-02-2018 11:39am

Got an update email from TII & Cork City/County Councils!

There are ongoing duct works for the N8 & N40 mentioned but I'll just stick to the Dunkettle segment:

Dunkettle

Site Investigation Works are well underway on the Dunkettle Interchange Site. The photograph attached shows ongoing Clearance Works near the Pfizer Plant south of the existing N25. Site Clearance Works have progressed slightly quicker than anticipated and we now hope to complete under this heading by the end of February 2018.

Over the next few weeks the Works will become increasingly visible to passing motorists. By the middle of next week, we expect to be clearing the traffic island at the Bury's Bridge "left in/left out" Junction, east of the Dunkettle Roundabout. This area will take a few days to clear and we will then Progress to the area north of the existing N25 immediately west of the Dunkettle Roundabout. No traffic lane closures will be required as a result of the upcoming works and we do not anticipate that the Works will cause any traffic disruption.

As noted in previous updates, the Site Clearance will be followed by Archaeological Investigation Works which will take 3-4 months to complete. We also hope to appoint the Main Works Contractor over the next few months with Offline Works then expected to get underway before the end of 2018. Further details to follow in future updates.

They sent a nice picture of a digger on a ditch too.

Anyway it's good to see decent progress there.

Jeju · 18-02-2018 11:32pm

I have not seen any plans for the completed works yet. Will the tunnel still be the only road taking all this traffic west bound? It will work a dream for traffic east bound, barring any accidents in the tunnel should a bridge no be considered to take traffic off straight up the M8.

AugustusMinimus · 19-02-2018 1:29am

Jeju wrote: »

I have not seen any plans for the completed works yet. Will the tunnel still be the only road taking all this traffic west bound? It will work a dream for traffic east bound, barring any accidents in the tunnel should a bridge no be considered to take traffic off straight up the M8.

Not entirely sure what you’re trying to say. All major movements are going to be free flow except for M8 South to Tivoli Dual Carriageway.

hans aus dtschl · 19-02-2018 10:06am

And pedestrians/cyclists will no longer be free flow either, obviously.

AugustusMinimus · 19-02-2018 10:22am

hans aus dtschl wrote: »

And pedestrians/cyclists will no longer be free flow either, obviously.

I have never in my life seen a pedestrian go through this junction.

It is also illegal for a cyclist to use either the tunnel or the M8 arms. Why won’t cyclist be able to use the new junction for other movements?

hans aus dtschl · 19-02-2018 10:57am

AugustusMinimus wrote: »

I have never in my life seen a pedestrian go through this junction.

It is also illegal for a cyclist to use either the tunnel or the M8 arms. Why won’t cyclist be able to use the new junction for other movements?

I didn't say that cyclists wouldn't be able to use the new junction, rather that they won't be free flow in the new design.
Since you asked though, in realistic and practical terms, requiring people to cycle on a footpath and cross an unsignalised motorway slip road in order to navigate the new junction will effectively remove cycling from the area as a mode of transport. We've discussed all this at length on here previously. The design is essentially ignorant of pedestrians and cyclists' needs, where it would have been relatively easy to accommodate them in a multitude of different (and cheap) ways.
My personal favourite solution would be the same one employed on the Mahon side of the tunnel: allowing them to use the (existing) road-to-nowhere over the tunnel.

FWIW, I have seen pedestrians on this junction more than once. They've been quickly intercepted by gardai. The lack of accommodation of pedestrians in the original east-west movement was the issue, as some people do attempt to move between Glounthaune and Tivoli areas.

AugustusMinimus · 19-02-2018 11:43am

hans aus dtschl wrote: »

I didn't say that cyclists wouldn't be able to use the new junction, rather that they won't be free flow in the new design.
Since you asked though, in realistic and practical terms, requiring people to cycle on a footpath and cross an unsignalised motorway slip road in order to navigate the new junction will effectively remove cycling from the area as a mode of transport. We've discussed all this at length on here previously. The design is essentially ignorant of pedestrians and cyclists' needs, where it would have been relatively easy to accommodate them in a multitude of different (and cheap) ways.
My personal favourite solution would be the same one employed on the Mahon side of the tunnel: allowing them to use the (existing) road-to-nowhere over the tunnel.

FWIW, I have seen pedestrians on this junction more than once. They've been quickly intercepted by gardai. The lack of accommodation of pedestrians in the original east-west movement was the issue, as some people do attempt to move between Glounthaune and Tivoli areas.

The obvious solution is a new greenway from Tivoli which would provide access to both Glounthaune and Little Island. Cyclists and pedestrians should be banned from the N25. Simply too dangerous.

hans aus dtschl · 19-02-2018 12:37pm

AugustusMinimus wrote: »

The obvious solution is a new greenway from Tivoli which would provide access to both Glounthaune and Little Island. Cyclists and pedestrians should be banned from the N25. Simply too dangerous.

I'm all for that, but two very obvious notes:
1: We need to remove houses from the N25.
2: We need a passable alternate route. It wouldn't necessarily have to be a full greenway (which most people love) but even a shared-use local road. This is done a lot in France and Germany and behaves a little like a greenway that locals can drive on, very slowly and for short dead-end sections.
Some sections of the old Cork-Waterford road (the really old Cork-Waterford road) have this configuration.
It's so much easier to do all this at the overall design phase than retrospectively, and it's low relative cost so there's very little excuse for the poor pedestrian/cyclist design in the interchange upgrade plan.

Edit:
ABP seem to have rejected the original cycle/pedestrian design anyway in the 23-April-2013 conditions, so that's good.

spacetweek · 19-02-2018 11:10pm

hans aus dtschl wrote: »

We've discussed all this at length on here previously. The design is essentially ignorant of pedestrians and cyclists' needs, where it would have been relatively easy to accommodate them in a multitude of different (and cheap) ways.

No cyclist or pedestrian would ever want to pass through such a sprawling and oppressive interchange anyway.
The old N25 is being reinstated, can't that be used to get through the junction?

AugustusMinimus · 19-02-2018 11:24pm

spacetweek wrote: »

No cyclist or pedestrian would ever want to pass through such a sprawling and oppressive interchange anyway.
The old N25 is being reinstated, can't that be used to get through the junction?

It will truly be the most fascist of junctions.

hans aus dtschl · 20-02-2018 11:48am

spacetweek wrote: »

No cyclist or pedestrian would ever want to pass through such a sprawling and oppressive interchange anyway.
The old N25 is being reinstated, can't that be used to get through the junction?

The old N25 or Old Youghal Road as it maybe was called back then would be a big improvement, but they won't use it. The way they've incorporated it into the new solution still isn't ideal:

Part 8 report here:
http://www.corkcoco.ie/sites/cork-cms/files/2018-01/32107200%20Part%208%20Cycle%20Report%20Rev1.pdf

Drawings here:
http://www.corkcoco.ie/sites/cork-cms/files/2018-01/32107200-CYC-P8-001%20Rev1%20A1.pdf
http://www.corkcoco.ie/sites/cork-cms/files/2018-01/32107200-CYC-P8-002%20Rev1%20A1.pdf
http://www.corkcoco.ie/sites/cork-cms/files/2018-01/32107200-CYC-P8-003%20Rev1%20A1.pdf

There's a nice bit of kerb-hopping, giving way to motorized traffic, shared footpath between cycles and pedestrians, and lots of roundabouts. It's further to traverse as a pedestrian than in a car.

hans aus dtschl · 20-02-2018 12:15pm

The new design sees a new pedestrian bridge over the railway by North Esk, and lots of new footpaths.

I've contacted them to say that the solution on Glashaboy bridge could be provided at the south of the bridge, linking over the tunnel quite cheaply (mirroring what's in Mahon, basically) for people intending to pass south of the junction to Little Island.

In a much more expensive design, perhaps the new railway pedestrian bridge they've put in at North Esk could be provided further down the Old Youghal road, across both railway and motorway into the back of Eastgate.

As we all say, why not just use the old N25/old Youghal Road alignment?
If you look carefully there's something being planned for that space, in this design. We can't see what that something is, but it's getting its own large roundabout, while none of the side-roads around it do! If this is to be the location of a new park and ride, surely it would only benefit from a greenway type design passing through it.

Live at Three · 25-02-2018 10:51pm

Why is traffic coming from the Dublin side of Dunkettle so much lighter on Friday mornings?

pigtown · 26-02-2018 7:23pm

I've given up trying to predict Cork traffic, it seems to be in different spots every day

Truckermal · 26-02-2018 8:15pm

pigtown wrote: »

I've given up trying to predict Cork traffic, it seems to be in different spots every day

I had a reasonably good run from the Dublin side this morning at 8.30am but then I was stopped in the Tunnel and crawled all the way the Douglas flyover, I don't think the upgrade will benefit west bound traffic unless they sort out the traffic merging from Bloomfield.

Traffic is always quiet on a Friday morning and has been for years.

grogi · 26-02-2018 8:53pm

Truckermal wrote: »

I had a reasonably good run from the Dublin side this morning at 8.30am but then I was stopped in the Tunnel and crawled all the way the Douglas flyover, I don't think the upgrade will benefit west bound traffic unless they sort out the traffic merging from Bloomfield.

By such logic no upgrade is worth doing because in the end you'll park on the M50...

The upgrade will benefit those exiting to Mahon and N28, won't it?!

pigtown · 26-02-2018 9:43pm

In the past few weeks the traffic has been at Dunkettle (45mins one morning), the M40, Kinsale Road roundabout, and Togher flyover, but on different days. Can't see a pattern for it though.

Live at Three · 26-02-2018 9:47pm

Truckermal wrote: »

Traffic is always quiet on a Friday morning and has been for years.

But why?

Carawaystick · 26-02-2018 11:36pm

Less people work on Fridays. People take long weekends; people on Parental leave take Monday or Friday most often in my experience; people take public transport to have a few pints after work.

Roads are capable of taking traffic until they're not, then it clogs, so reducing traffic by a small fraction, can have dramatic effects on the free flowing nature of the traffic.

CHealy · 05-03-2018 4:52pm

Huge clearing work ongoing to the North East & East of the roundabout itself, all trees and hedging cleared from the Little Island slip all the way over to the slip off to Burys Bridge. Passed by awhile ago and they had stop/go in operation while they brought down the larger trees.

Pteppic · 15-03-2018 12:15am

Bacchus wrote: »

^
This.

Delays through both are reasonable at the moment (2 minutes at Lakeview, 5 minutes as Castlemartyr... when I am typically going through in evening) but if there's an unbroken flow of traffic coming from the South ring and Dunkettle Roundabout I can easily see these becoming even greater bottlenecks. Not to mention how much the queue of traffic taking the first exit for Middleton will back up (due to traffic light system)... likely spilling onto the dual carriageway.

I assume you mean a 2 minute delay at Lakeview going east in the evening. It's much, much worse than that coming from Whitegate or Youghal in the mornings.

Bacchus · 15-03-2018 11:06am

Pteppic wrote: »

I assume you mean a 2 minute delay at Lakeview going east in the evening. It's much, much worse than that coming from Whitegate or Youghal in the mornings.

Yes. It's much worse in the morning yes, but that won't be affected by a free flowing dunkettle.

marno21 · 16-03-2018 12:42am

Bacchus wrote: »

Yes. It's much worse in the morning yes, but that won't be affected by a free flowing dunkettle.

Only difference is that a free flowing Dunkettle may entice further commuters from east of Midleton, but that's outside the scope and is difficult at best to measure.

Bacchus · 16-03-2018 12:08pm

marno21 wrote: »

Only difference is that a free flowing Dunkettle may entice further commuters from east of Midleton, but that's outside the scope and is difficult at best to measure.

Yeah, there might be a more long term knock on effect in that sense.

AugustusMinimus · 16-03-2018 4:42pm

Given the distance between Dunkettle and Middleton I don’t think it will have a huge effect on traffic going East on the N25. Certainly the traffic light sequence could be adjusted outside Abernethy’s to reduce any potential tailbacks into the N25.

I still say a third junction should be built for Little Island where the KFC sign is when heading west on the N25. I’d also have another bridge over the N25 linking Little Island to Glounthaune without any N25 access.

The biggest issue on the South Side of the city is that practically every road which crosses the SRR also has a junction in it. This is not a good idea. More junctionless crossings are required.

mydiscworld · 20-03-2018 4:22pm

So when the Dunkettle upgrade is completed will this mean more traffic queuing on N40 to get to Mahon Point/ City Gate?

That junction is already over capacity, with plans for even more office blocks to be built

marno21 · 20-03-2018 4:29pm

mydiscworld wrote: »

So when the Dunkettle upgrade is completed will this mean more traffic queuing on N40 to get to Mahon Point/ City Gate?

That junction is already over capacity, with plans for even more office blocks to be built

Yes there will be a longer queue on the off ramp of the N40 at the Mahon junction. I wouldn't be surprised if traffic light sequences were adjusted to account for this tho

marno21 · 06-05-2018 12:37am

Contractor to be appointed for Dunkettle Interchange scheme in June

https://twitter.com/CISireland/status/992338966836850688

Work to begin in full in Q1 2019. Preliminary work will be ongoing during Q4 2018. The scheme will take 3 years or so due to complex traffic management required along the route.

marno21 · 08-05-2018 6:19pm

Tender out for archaelogical works to take place in advance of full works starting in Q1 2019

https://irl.eu-supply.com/app/rfq/publicpurchase.asp?PID=128832

coL · 09-05-2018 10:44am

Anyone any idea of which contractors/consortiums are bidding for this or where to find this info?

DerMutt · 20-05-2018 10:42am

The latest email update from Cork County Council:

Dunkettle

As regular commuters will know, the site clearance works at the Dunkettle site have been completed. We have also completed follow on survey works throughout the site. The next step is to investigate the site from an archaeology point of view and resolve any sites uncovered – this archaeological contract will be getting underway shortly and we expect it to reach completion before the end of the summer with no traffic disruption arising.

The tender process for the Main Contract is progressing and we now hope to appoint the Contractor before the end of June 2018. A four-year delivery period is envisaged with details to follow in future updates.

annfield1978 · 20-05-2018 8:27pm

Letters to Contractors may have already gone out...

Aontachtoir · 22-05-2018 2:56am

Nice little article in the Echo about the Dunkettle project, although it doesn't add much about timelines beyond the email DerMutt shared yesterday. The picture in the article (rather small) shows how much land has been cleared around the roundabout. If any kind person were willing to share some pictures of the site from closer up it would be greatly appreciated... :angel:

Separately, in the picture it looks like the old Glounthaune road which is due to be reopened after the works is entirely blocked off by the M8. I had assumed that there was a tunnel underneath the motorway but I guess I was wrong.

http://www.eveningecho.ie/corknews/Site-works-completed-for-Dunkettle-upgrade-5d2768d8-320b-4ca4-a422-e88f7d9d0421-ds

Edit: After looking more closely on Google Maps it's pretty obvious that the old road is entirely blocked off by the M8's earthworks. Lots of tidying up to be done down there.

AugustusMinimus · 22-05-2018 7:21am

There people on the Echo Facebook page moaning firstly and the price and secondly about the future roadworks. Echo Facebook page is moan central. New jobs get announced and people still moan.

Taking a look on Google Maps it’s interesting to see that part of the old road entering Little Island West still exists in no mans land. There’s an inhabited house beside this old bit of road which I presume has been CPO’ed too.

hans aus dtschl · 22-05-2018 9:35am

I don't fully understand what you guys are talking about regarding the old road and the west entrance to Little Island, but here goes...

The old road mentioned by Aontachtoir is going to be joined up by roundabout (park and ride?) to the east of the M8, and partially a cycle path to the west of the M8.

I don't think any existing houses are affected or CPO'd: at least none that I can make out.

Here's a drawing set on Cor Co. Co. website which may help everyone to be on the same train of thought:
https://www.corkcoco.ie/sites/default/files/2018-01/32107200-CYC-P8-003%20Rev1%20A1.pdf
https://www.corkcoco.ie/sites/default/files/2018-01/32107200-CYC-P8-002%20Rev1%20A1.pdf

AugustusMinimus · 22-05-2018 9:59am

hans aus dtschl wrote: »

I don't fully understand what you guys are talking about regarding the old road and the west entrance to Little Island, but here goes...

The old road mentioned by Aontachtoir is going to be joined up by roundabout (park and ride?) to the east of the M8, and partially a cycle path to the west of the M8.

I don't think any existing houses are affected or CPO'd: at least none that I can make out.

Here's a drawing set on Cor Co. Co. website which may help everyone to be on the same train of thought:
https://www.corkcoco.ie/sites/default/files/2018-01/32107200-CYC-P8-003%20Rev1%20A1.pdf
https://www.corkcoco.ie/sites/default/files/2018-01/32107200-CYC-P8-002%20Rev1%20A1.pdf

I think you’re right re CPO. M8 to N25 slip is getting quite near a house though.

The old N25 used to go under where the M8 is now. However, there is no present tunnel under the M8. A tunnel will have to be created for it.

hans aus dtschl · 22-05-2018 12:34pm

AugustusMinimus wrote: »

The old N25 used to go under where the M8 is now. However, there is no present tunnel under the M8. A tunnel will have to be created for it.

What tunnel? The N40-N25 East slip, south of the rail line is it?
Maybe just a bridge on the southbound M8 straight-through lane(s).

Cycles / pedestrians planned to share with traffic under the bridge of the M8 / L2999, north of the rail line.

Chris_5339762 · 22-05-2018 7:44pm

Yes the old N25 did go under where the M8 is now. This is old-old N25, before the East Cork Parkway (Dunkettle Roundabout to Cobh) was built. You used to drive through Glounthaune. You can still see some of the old-old N25 from the train.

https://goo.gl/maps/WUYxsiwk7gn

Follow the line of it to the west to where it joins up at Dunkettle House. By the way, there are no tunnels, the other roads were built over it. Must go for a walk along it someday.

deRanged · 24-05-2018 8:48am

this might help to show the old road, taken from the Midleton train this morning.

https://www.youtube.com/watch?v=4Fwo75ToxVY

hans aus dtschl · 24-05-2018 9:49am

Thanks deRanged.
I know hindsight is 20:20 but what a shame they didn't think to put in a wider train tunnel in the first build, and provide an East-West cycle/pedestrian route.

marno21 · 18-06-2018 1:08am

Should find out in the next few weeks who will be responsible for letting us watch this daily event come to an end

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

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