N8/N25/N40 - Dunkettle Interchange [under construction]

DylanQuestion

I keep bringing this sign up but can someone explain the rationale behind it? Especially when it's straight up wrong. Left is for Limerick and the North Ring Road when you get onto the N8, right is for City Centre. Also, what's the difference between Cork and City Centre?

Chris_5339762

...and just to say in general that widening the tunnel will really have no impact OVERALL unless the entire South Ring was widenned to the Kinsale Road flyover, including the Douglas Viadust.

And sadly the North Ring would be a better investment of cash.

niloc1951

https://www.boards.ie/discussion/comment/121755338#Comment_121755338

Plus, it's over 6km before the actual divide, which, as you say is actually the reverse of what the sign indicates. The left lane is for Limerick and the right lane is for Cork/Cork City Centre.

According to the Rules of The Road, at that point, all traffic should be driving in the left lane and only overtaking traffic should be using the right lane. The road at that point being nearly 3km away from the next junction (the roundabout to the R639)

Jayuu

https://www.boards.ie/discussion/comment/121755338#Comment_121755338

Is that the replacement of this sign? Doesn't make much sense all right. The old signage seems far simpler to understand.

Also can I ask what is currently painted out on that sign? Is it the M8 North for Dublin (as shown on the old sign above). I assume that the current small blue M8 Dublin splash currently under Limerick will be removed from the sign when it's unpainted? Otherwise it's going to be incredibly confusing.

As a general question who tales responsibility for signage? Is it TII or the road designers?

DylanQuestion

Yup, that's the old sign, and I assume you're right about that being the M8 (Link C?) and the one under Limerick will be removed

Jayuu

https://www.boards.ie/discussion/comment/121755639#Comment_121755639

In which case as I said above the old sign was far more clearer than the new sign. I really would love to ask the person who designed this sign what their logic was here.

DylanQuestion

https://www.boards.ie/discussion/comment/121755660#Comment_121755660

Same, I just emailed the email provided on the last page asking about it

yagan

https://www.boards.ie/discussion/comment/121755506#Comment_121755506

A north city link would take all m8 traffic bound for west cork away from the tunnel at least.

cork_south

Not a great morning to be celebrating the opening of the free flow DKI with the weekly crash at Bloomfield bringing the whole interchange to a standstill again.

niloc1951

Here's a novel idea, in this country at least.

Designate the right lane (lane 2), from after the exit ramp to jct 10 (Mahon) to after the on ramp of jct 8 (Douglas West), as an 'express lane'.

With a physical separation using the commonly used plastic bollards.

Such an express lane would provide an uninterrupted westbound route, with no weaving, for traffic heading from the JLT to jct 6 and beyond.

Chris_5339762

Sou

https://www.boards.ie/discussion/comment/121756526#Comment_121756526

Exactly the same spot where someone went into the back of me a few months ago. Its poor driving, tailgating, jumping lanes, yknow the usual. And it is a very poorly designed merge.

An 80kmh limit (enforced) between the tunnel and Kinsale Road would at least stop some of this rear ending going on.

Edit: Rush hour only. Or at least go the whole hog and do variable speed limits. Enforced.

MrDerp

https://www.boards.ie/discussion/comment/121756770#Comment_121756770

Collector Distributor? Ever driven the 401 in Toronto?

DylanQuestion

https://www.boards.ie/discussion/comment/121756770#Comment_121756770

I think one big thing people would claim is an issue to prevent this are ambulances/fire engines not being able to swap between lanes in an emergency. Otherwise, I think it would solve a lot. Also, people coming from the N28 onto the N40 in the right hand lane don’t realise to the last second that the left hand lane has priority when they become one lane, and so they try to merge onto the N40 before it’s even allowed. That probably slows traffic down too. I always drive to the end of the slip lane (or as close as I can get) and it’s so much smoother merging in

niloc1951

No, but I am aware of the concept and its use to provide an interrupted route for through traffic.

cork_south

The main issue I see at Bloomfield is you have traffic merging at different points, some across continuous white lines, all along the 500m stretch bringing traffic to a standstill on the N25.

Added to this as soon as they merge many drivers are looking to get into the right hand lane as soon as possible, aggressively - causing the crashes we see constantly.

Adding to the existing bollards as follows ensuring correct merging at the end of lane wouldn't entirely fix the issue but would certainly help.

The queuing at this junction should be on the N28, not on the N40 (in my opinion)

DylanQuestion

It’s really frustrating that we can all come up with these potential solutions to the N40 problems, which could be implemented and rolled back easily, but the people who can actually make these changes don’t seem to be doing anything (publicly, at least)

niloc1951

https://www.boards.ie/discussion/comment/121757076#Comment_121757076

Use of https://www.pittman.ie/collections/rubber-bollards would facilitate emergency vehicles to change lanes when necessary

Mefistofelino

https://www.boards.ie/discussion/comment/121757463#Comment_121757463

Once they can be driven over by a vehicle, any van or truck is going to regard them as fair game. Look at the quantities of them that have been driver over, broken or ripped out where they have been used as "segregation" for bike lanes.

dontwatchtrailers

https://www.boards.ie/discussion/comment/121757137#Comment_121757137

This 100%. Such a change could be done over night and I can't imagine it would do anything other than cause less dangerous merges. Surely the people who designed these roads are aware they're not being used properly (and crashes occur as a result) and as such something should be done about it.

hans aus dtschl

https://www.boards.ie/discussion/comment/121757597#Comment_121757597

The roads in question were designed a very long time ago when traffic was nowhere near current levels and nobody imagined that the city would expand the way it did. Current designers are now firefighting a distributor/bypass mess. The primary way these roads are being used incorrectly is by thousands of short-distance commuters, and "N40 upgrades" will struggle to deal with that.

DylanQuestion

https://www.boards.ie/discussion/comment/121757807#Comment_121757807

Especially when Bus Connects is advising those outside the N40 in the City South East to stop driving on the R610 to the City Centre and instead use the J7 and J9 on ramps to get to the N40 and N27!

rameire

New Link just open

serfboard

https://www.boards.ie/discussion/comment/121757807#Comment_121757807

According to TII "Traffic volumes through the interchange are at an all-time high approaching 120,000 vehicles on the busier days of the week". Holy God.

Padraig Mor

https://www.boards.ie/discussion/comment/121758326#Comment_121758326

I see from their PR that TII are now in the misinformation business, claiming that "journey times during peak hours have been reduced by almost 50% on average as a result of the upgrade project". I'd be very interested in which 'average' they are using for this calculation - mean/median/mode - and how it was calculated as I'd be very hesitant to believe that everyone using the interchange is experiencing an average 50% reduction. In particular they claim "journey time savings of almost 60% are being achieved on the N40 to N25 route during peak hours, whilst time savings of over 50% are being achieved on routes accessed via the M8 Southbound" - scrupulously avoiding mention of journey times from the N25 eastbound which carries far more traffic than the M8 southbound and which have seen little improvement, and in fact possible worsening! Also, what exactly does "journey time savings of almost 60% are being achieved on the N40 to N25 route during peak hours" mean? I suspect it's measured from after the Mahon junction and through the tunnel which has undoubtedly improved - but ignoring the mile long tailback before the Mahon junction doesn't reflect the real life journeys of people using the tunnel.

KrisW1001

They have data on over 100,000 movements a day. You have personal anecdotes of one driver. I'll trust them.

I used to work with traffic data, and the one thing you see straight away is that it's very random: you can be "delayed" while someone just three or four minutes behind you will sail through. The only way to get sense from it is to look at thousands of journeys at a time.

My own anecdotes, just as worthless as yours, are that N40/N25 is far faster both ways than it was before. My previous experience was of tailbacks before Mahon, then stop-go through the tunnel lights. Now it's a steady if slow progress at busy times.

Coming the other way, there's just no comparison to before.

Chris_5339762

https://www.boards.ie/discussion/comment/121757137#Comment_121757137

... its also on a bend. And before it is another bend. Sightlines aren't great, especially at night. And because that part of the SRR isn't lit.

They should delay the merge until it straightens out before the actual Douglas Viaduct. Would at least force people to merge on a straight bit.

Hibernicis

Dronehawk posted a video showing his first drive over Link C today, plus two others, a retrospective on the construction of the Rail overpass and a Link C taster posted at the weekend

• Dunkettle's Finished - First drive on Link C - https://www.youtube.com/watch?v=YnVfnqwIRsM
• Railway Overpass Rebuild - https://www.youtube.com/watch?v=RpGqd1l6M98
• Final Dunkettle Link opening this weekend - https://www.youtube.com/watch?v=XMF9cUqowXo

Once again, I'd like to salute Dronehawk for bringing this project alive over the last few years, and hope that they continue the amazing work with coverage of the M21, M28, M20 (hopefully), the Killaloe Bypass, the Foynes freight line reopening, Midelton to Glounthane double tracking, other CART work, the Midleton to Youghal Greenway and anything else that comes along.

For anyone that would like to acknowledge the time and effort that Dronehawk has put into documenting this and other projects, they have posted a "buy me a coffee" link on a number of their videos and now might be a good time to show appreciation.

Hibernicis

TII have also published an overview of the project, including a lot of stats - https://www.youtube.com/watch?v=-tl3Uh7scLA

confidentjosh

https://youtu.be/zASDfuTa_sk

DENtv drive through new link