M11/N11 - M50 (J4) to Coyne's Cross (J14) [options published]

Times report on the tunnel option:
https://www.irishtimes.com/news/ireland/irish-news/details-of-new-road-tunnel-at-glen-of-the-downs-released-1.4542500

Like I've said before on here, I think the cyan route is the better route, but its too late for that. If they are going to cpo huge chucks of countryside it should be for a new trainline (I know that will be multi billion price tag).
Link roads, closing unnecessary junctions and entrances plus making best use of the existing corridor is the way to see this through. And I say that as someone who's family home will be effected by the red route.

prunudo wrote: »

That would allow Barry's bridge to become one way and return to being used as an on ramp. ( is my mind getting fuzzy or was it origanlly one way, can't remember).

Barry's Bridge was built in the 70s and you're right it was one-way until about 10 years ago when they built an exit lane there to (belatedly) replace the closed median crossing at Willow Grove. The local bus service (184) still doesn't use the new slip road though, it goes up to the Glenview, does a u-turn and exits on the southbound side.

They left several minor accesses along that stretch that should have been closed when J11 opened, at Kilpedder, Willow Grove and Old-Downs road.

You can't walk or cycle from Newtown to Kilpedder without using the N11, which is ridiculous, a short link road from J12 is needed. And whilst you can walk from Willow Grove to Delgany via Barry's Bridge, you can't cycle that way so have to take a massive detour via the R774 or cycle along the N11.

I've no problem with them fixing these local access issues, which will in turn improve traffic flow on the N11, but I'm still not in favour of a massive expensive upgrade of the dualler itself (particularly not the cyan route which would involve blowing huge holes in Downs Hill).

prunudo wrote: »

I agree, just not sure why they've really explored this option.
Parallel link roads would solve a lot of the congestion issues at peak times. There are far too many local traffic movements interacting with mainline traffic which in turns contributes to the stop start nature of traffic flow.
Netwown/Kilpedder/Willow grove residents going to Greystones/Delgany (Jn12-jn10). Roundwood/Kilmacanogue residents going to Bray (jn8 -jn 7) and Enniskerry residents goings Bray also (20 bends to jn6).
Also people turning off to Enniskerry, going from mainline or from jn7 are at odds with movements of traffic joining mainline from jn7.
When you actually sit down and think about it the whole section of road is a shambles. Doesnt know whether its a main interurban or a local road.

Yep totally agree with all of the above which is why I think the best solution is focus turning that stretch of N11 into a road that serves the local traffic and go with the cyan for interurban traffic.

It just seems so obvious. I'm not sure the cost would be much higher either by the time you mess about with flyovers and parallel link roads to try and solve both problems.

schmittel wrote: »

Loyatemu's suggestion looks like a neater job than a flyover to achieve the same thing.

I agree, just not sure why they've really explored this option.
Parallel link roads would solve a lot of the congestion issues at peak times. There are far too many local traffic movements interacting with mainline traffic which in turns contributes to the stop start nature of traffic flow.
Netwown/Kilpedder/Willow grove residents going to Greystones/Delgany (Jn12-jn10). Roundwood/Kilmacanogue residents going to Bray (jn8 -jn 7) and Enniskerry residents goings Bray also (20 bends to jn6).
Also people turning off to Enniskerry, going from mainline or from jn7 are at odds with movements of traffic joining mainline from jn7.
When you actually sit down and think about it the whole section of road is a shambles. Doesnt know whether its a main interurban or a local road.

prunudo wrote: »

Not sure why a parallel link road isn't or hasn't been looked at in the past.
I believe a flyover at the old Drummin junction is planned to connect Willow and Delgany. That would allow Barry's bridge to become one way and return to being used as an on ramp. ( is my mind getting fuzzy or was it origanlly one way, can't remember).

Loyatemu's suggestion looks like a neater job than a flyover to achieve the same thing.

loyatemu wrote: »

they can move the forest car park. the only on-ramp right at the Glen is J10 and I assume they'll be closing the Old Downs Rd turn adjacent to it which will make more space.

(J10 is a mess of old roads really, it might be better if they closed it and built a link road from there to J11 for access to Delgany. The roundabout at J11 already has unused arms for that and a link to Kilquade).

Like this:

Not sure why a parallel link road isn't or hasn't been looked at in the past.
I believe a flyover at the old Drummin junction is planned to connect Willow and Delgany. That would allow Barry's bridge to become one way and return to being used as an on ramp. ( is my mind getting fuzzy or was it origanlly one way, can't remember).

Also agree on moving the forest car park. Makes far more sense to move it to the rear of the woods with direct access from jn9, safer both for traffic movements and security but also allows for more space and even future opportunities for venders/other service's.

L1011 wrote: »

All of the uproar for little of the benefit.

Also doesn't deal with the entrance from the S/B side which would be ever more dangerous on a three lane road; the onslips on the N/B side would be very dangerous on a narrow three laner too.

they can move the forest car park. the only on-ramp right at the Glen is J10 and I assume they'll be closing the Old Downs Rd turn adjacent to it which will make more space.

(J10 is a mess of old roads really, it might be better if they closed it and built a link road from there to J11 for access to Delgany. The roundabout at J11 already has unused arms for that and a link to Kilquade).

Like this:

L1011

Chris_5339762 wrote: »

I think it'll be the red route purely for sanity reasons. The N11 through the Glen is just too new to replace with an offline route.

That said.. widening it... maybe by a token amount? Fit in three narrow M50 width lanes into a very slightly widened corridor?

All of the uproar for little of the benefit.

Also doesn't deal with the entrance from the S/B side which would be ever more dangerous on a three lane road; the onslips on the N/B side would be very dangerous on a narrow three laner too.

Chris_5339762

I think it'll be the red route purely for sanity reasons. The N11 through the Glen is just too new to replace with an offline route.

That said.. widening it... maybe by a token amount? Fit in three narrow M50 width lanes into a very slightly widened corridor?

Pete_Cavan wrote: »

Many here don't want to hear this but they could go with red but not widen the N11 through the Glen.

I really hope they're not that stupid. But looking at their interactive map, their corridor certainly narrows through the Glen to very little more than is there already!

prunudo wrote: »

Personally think, for longevity and future proofing, the cyan route or similar is a better route than what the red route has become.
But, that ship has sailed, its 40 years too late, I think the current cyan route will meet a lot of local opposition, but then the red route will meet outside opposition and more likely to end up in the courts. Its going to be a conundrum for the designers, thats for sure.

Agree on the cyan route, it's a far better long term solution.

They'll meet opposition whichever way they go.

Cyan opposition will be largely disgruntled locals bearing the brunt of the CPOs. Their case will be principally property rights etc.

Red opposition will have a stronger case, be better funded, better organised with a larger reach.

I think they'll have a far harder job overcoming the opposition to the red route.

Pete_Cavan wrote: »

Many here don't want to hear this but they could go with red but not widen the N11 through the Glen.

Interestingly, that thought crossed my mind recently too, widening as far as jn10, new northern link road to Greystones and let the future politicians worry about jn10-14 in 2040.

schmittel wrote: »

......

.......

Personally think, for longevity and future proofing, the cyan route or similar is a better route than what the red route has become.
But, that ship has sailed, its 40 years too late, I think the current cyan route will meet a lot of local opposition, but then the red route will meet outside opposition and more likely to end up in the courts. Its going to be a conundrum for the designers, thats for sure.

Pete_Cavan

Many here don't want to hear this but they could go with red but not widen the N11 through the Glen.

prunudo wrote: »

First time seeing that purple route. The level of detail on the red route would lead me to think thats the one they're going for, although maybe reading too much into it. Must ask the parents if they've received anything official from arup recently.

Few interesting additions including jn7 link roads. Interesting alignment at jn9 too, possibly for future northern access route to Greystones. Also a link road at jn11 linking Kilquade road to Farrenkelly rd.

I raised the is red the preferred route because of level of info/detail question in previous discussions with ARUP, and they said that because there is already a road on the ground they are inevitably significantly more informed about what is likely and what is not if they chose that route. They said not to read too much into the level of detail they have with red. Kind of makes sense when you think about it.

I'm currently thinking they are leaning towards cyan route because of the sudden introduction of the tunnel option. This clearly seems like a red herring, it wont be the preferred route, and has been introduced at a late stage in order to justify the preferred route.

If preferred route was red yes they'd have to show that they have considered all possible alternative options in order to justify going through the Glen SAC. But surely if the tunnel is there to tick the all other boxes for the Habitats Directive, they'd have done more public consultations on it and at least appeared to be more thorough etc? If they go red it is inevitable it will end up in court challenged because it is in contravention of European law, so they would need to have crossed every T and dotted every I to defend that challenge.

Which leads me to think it is there to justify the cyan route. If they go for that, there will be a huge uproar about cost, "awful waste of money, when you could have just widened the existing road, we don't need a new motorway", they can say look widening the N11 through the Glen is not an option, and the only other feasible option is a tunnel, and that is three times the cost or whatever.

Possibly overthinking this I admit, but have had plenty of time on my hands!

loyatemu wrote: »

is this new? interactive map of the current options:
https://atlas-ie.arup.com/portal/apps/webappviewer/index.html?id=a47cd00abeee44a49cfdfed7a8993da8&fbclid=IwAR1hSmO8aFdqtt63AiuJVTy-FFTHjNOYGAuQk1Y67NF9a3HLVs73SPQvn7Q

First time seeing that purple route. The level of detail on the red route would lead me to think thats the one they're going for, although maybe reading too much into it. Must ask the parents if they've received anything official from arup recently.

Few interesting additions including jn7 link roads. Interesting alignment at jn9 too, possibly for future northern access route to Greystones. Also a link road at jn11 linking Kilquade road to Farrenkelly rd.

loyatemu wrote: »

is this new? interactive map of the current options:
https://atlas-ie.arup.com/portal/apps/webappviewer/index.html?id=a47cd00abeee44a49cfdfed7a8993da8&fbclid=IwAR1hSmO8aFdqtt63AiuJVTy-FFTHjNOYGAuQk1Y67NF9a3HLVs73SPQvn7Q

Looks new it says in the bottom right about the study they are doing now, so prob new

schmittel wrote: »

Certainly new to me. Is that purple corridor the tunnel?

it's not specified but I assume so as you couldn't build an overground road along that alignment. Probably some sort of scheme update imminent, the map was posted by one of the local reps on FB.

loyatemu wrote: »

is this new? interactive map of the current options:
https://atlas-ie.arup.com/portal/apps/webappviewer/index.html?id=a47cd00abeee44a49cfdfed7a8993da8&fbclid=IwAR1hSmO8aFdqtt63AiuJVTy-FFTHjNOYGAuQk1Y67NF9a3HLVs73SPQvn7Q

Certainly new to me. Is that purple corridor the tunnel?

is this new? interactive map of the current options:
https://atlas-ie.arup.com/portal/apps/webappviewer/index.html?id=a47cd00abeee44a49cfdfed7a8993da8&fbclid=IwAR1hSmO8aFdqtt63AiuJVTy-FFTHjNOYGAuQk1Y67NF9a3HLVs73SPQvn7Q

Pete_Cavan

Perhaps the combined cost of all potential routes might get you close to 2.3bn!

Sam Russell

Mod: Discussion of the price estimate for this project is a bit previous, and can only be considered devious. It will only divert this thread down a rabbit hole.

No route selection. No road type defined - motorway or DC? Will it be tunnelled? When will the work be started? Will it even be done?

Please wait until the preferred route is selected, and those questions above can be answered. They will have a large effect on the likely cost. There is plenty more to discuss.

Thank you for your understanding.

spacetweek

They haven't picked a preferred route and some routes need tunnels and some are just widening of the existing road. The price difference between those 2 is enormous.

Sam Russell wrote: »

What was the pay grade of the person that told you this?

lol No that was there original estimate a fair few years back.

Sam Russell

Steve012 wrote: »

Back when this came to the fore, I met with Arup they mentioned 2.3 for the scale of the project.

That's where I heard it.

What was the pay grade of the person that told you this?

KrisW1001 wrote: »

Phonecall:
TD: "how much does it cost to build a house?"
Engineer: "What kind of house?"
TD: "You know... a house. A nice one."
Engineer: "Without knowing what's needed, or the ground, or the access, I've no idea! It could cost anything: it could be 100k, or it could be over a million euro!"

Headline:
TD SAYS HOUSE TO COST "OVER MILLION EURO"

2.3 billion for this is a nonsense figure until the route, and thus the real scope of works, becomes known. And no, Arup does not know that route already. If they did, revealing this by telling you would land them in a lot of legal trouble.

Back when this came to the fore, I met with Arup they mentioned 2.3 for the scale of the project.

That's where I heard it.

KrisW1001

Phonecall:
TD: "how much does it cost to build a house?"
Engineer: "What kind of house?"
TD: "You know... a house. A nice one."
Engineer: "Without knowing what's needed, or the ground, or the access, I've no idea! It could cost anything: it could be 100k, or it could be over a million euro!"

Headline:
TD SAYS HOUSE TO COST "OVER MILLION EURO"

2.3 billion for this is a nonsense figure until the route, and thus the real scope of works, becomes known. And no, Arup does not know that route already. If they did, revealing this by telling you would land them in a lot of legal trouble.