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

Based off the latest newsletter it looks like the existing signage is correct for tunnel northbound.

Left hand lane for town and East Cork, right hand lane for Dublin.

There could potentially be a lane merge available after the Link D turnoff to the M8 though.

If the final design is to have the right hand lane M8 North only then the huge tailbacks at peak times will continue, with town and East Cork left lane only.

It's an 80÷/20÷ split from what I can see on the traffic cams. Seems a crazy decision (if it's the final design).

In effect, it is a slip, it’s just the advance signage on the tunnel entrance doesn’t make this clear. Coming from the tunnel, the two tunnel lanes fan out into four:

1. N8 City (not yet fully open)
2. N25 Little Island
3. N25 East
4. M8 North

To do what you propose, only the "Get in lane" advance sign at the south portal of the tunnel needs to change, so that drivers for N25 Rosslare end up in the same tunnel-lane as those for M8, and then split again, north of the tunnel, into their correct lanes..

One problem is the proximity of the Mahon Point on-ramp to the tunnel portal which creates mayhem as joining traffic needs to get to the second lane in a short distance. But that problem has been around a long time, and hasn’t been caused by the new interchange.

Ah, I didn’t see that... I was going by the original drawings, and it’s sometimes hard to see the exact lanes.

To solve the problem of the right lane being underused, you could change the sign on approach to the tunnel to this:

The difference is that N25 traffic is asked to use the right lane, not the left.

Once through the tunnel, a new lane opens to the left. I would have re-lined the road to make it appear to be a lane opening at right, and changed the gantry here to look like this:

Basically, Little Island traffic finds itself in the new left lane (they should have be in the previous left lane), along with the Cork traffic (in the final plan, that lane will split again into "Cork" and "Little Island"). The Waterford traffic that was in the rightmost lane bears left to avoid going to Dublin, and Dublin traffic, which was in the rightmost lane, “exits right”.

Nobody has to dash across traffic. Either stay where you are, or move one lane left, and the two tunnel lanes are better balanced.

From the picture it says that the right hand lane will close, which does give the impression that only left lane would be used for n25/little island. Where that lane goes under the existing flyover is needed for the n25w to m8n movement, but surely there's space for 2 lanes from tunnel to head to n25e/little island

The lane that will close will need to close for the N25W to M8N movement to be built - and presumably the old roundabout on that tide to be tarred etc.

I still hope both lanes coming out of the tunnel will be N25E, I think they will or the slip road would not be two lanes. But we haven't seen this confirmed or denyed anywhere yet.

Wonder should they try a temporary partition there (flexi bollards) back through the tunnel, if we see the same level of lane jumping we do at the moment confined to the space between the tunnel exit and M8N exit there's going to be chaos.

I actually think the slip road to glanmore/tivoli for the tunnel is key here as if that is completed properly they could use the additional wider area to facilitate the two lanes flowing to the N25E connections as below? Should leave sufficient space for the remaining works to be completed?

Latest Dronehawk video

Those orange barrier yokes might do the job by stopping folks pulling straight out into traffic and force them to merge properly towards the end of the merging lane.

Is that not the westbound offramp you're thinking of?

Cones on tunnel exit are set up as follows:

Lane 1: City or N25 East

Lane 2: N25 or new M8 slip road.

Interesting to see if this materialises in road markings and revised signage overnight.

No , northbound from MPSC

Have you got a link to that? The only project I saw in relation to the Mahon junction is the improvement of the N40W exit at Mahon - not the N40E entrance from Mahon.

Literally just witnessed a collision on the cameras from vehicles obviously not expecting to have to merge after the new slip, was a bus, 2 vans and few cars, lot of swerving last second to avoid anything

Edit: and another...car in left lane out of tunnel for some reason moves to right lane, thought needed go Dublin road but went past slip then swerved straight back in, but other car there.

Edit 2: and now a car has come to a full stop, reversed back to make the new slip.

Nearly got wiped out just now going to work , Land rover over pulled along side me just as we reached the Link D exit and discovered he had no choice but to go back into my lane just beyond the exit. How he didn't wipe me out i don't know. No signage warning drivers that right hand lane is for Dublin M8 only.