N3 - Clonee to M50

marno21

This is a plan to redesign and upgrade J2 on the N3 in Dublin:

http://irishcycle.com/2017/01/15/massive-blanchardstown-road-interchange-upgrade-mixes-cycling-and-walking/

Tender for ground investigation from Fingal County Council was put out yesterday.

Slippin Jimmy

Probably one of the worst junctions in Dublin. I'm glad to see that there are going to be changes made.

L1011

I'm not sure what they can do here beyond provide more space for queueing cars (and the ped/cycling improvements) - the interchange is compromised forever by the number of roads approaching it on the Blanchardstown side.

Middle Man

Indeed - I got my information on the scheme from the same source and as usual, the cyclists are whinging.

BelfastVanMan

Middle Man wrote: »

Indeed - I got my information on the scheme from the same source and as usual, the cyclists are whinging.

Quite why cyclist want to cycle along this stretch of road is beyond me.

Sam Russell

Middle Man wrote: »

Indeed - I got my information on the scheme from the same source and as usual, the cyclists are whinging.

Mod: @ Middle Man: Can you stop the constant carping about cyclists!

Many motorist are cyclists, and also pedestrians. The modal shift from cars to bikes and buses will make life easier for all if it reduces congestion - so be glad of it.

If you look at the above tweet and perhaps understand why cyclists may have a case against motorists who appear to think they can drive down a cycle path.

Sam Russell

Mod: I have deleted off topic posts. Please keep to the N3 and the Snugborough Interchange Upgrade.

roadmaster

L1011 wrote: »

I'm not sure what they can do here beyond provide more space for queueing cars (and the ped/cycling improvements) - the interchange is compromised forever by the number of roads approaching it on the Blanchardstown side.

I think you hit the nail on the head there. I sat on the N3 off ramp yesterday evening wondering how a extra bridge would help things but it's along time since I did road design maybe they will have a good plan. Due to the sheer volume of traffic I just can't see anything making a difference .would it maybe better to throw the towel in instead and forget the project. Maybe put the money to a some other project instead ?

spacetweek

roadmaster wrote: »

I think you hit the nail on the head there. I sat on the N3 off ramp yesterday evening wondering how a extra bridge would help things but it's along time since I did road design maybe they will have a good plan. Due to the sheer volume of traffic I just can't see anything making a difference .would it maybe better to throw the towel in instead and forget the project. Maybe put the money to a some other project instead ?

It's not the only project needed along here - the N3 mainline needs 6 lanes too.
The only thing for this junction if the current upgrade doesn't work is to look at trying to reroute away some of the roads that converge on it, or add new entrance and exit slips for them or something.

At least the pedestrian and cyclist facilities will be improved.

roadmaster

Would there be room to put in 2 extra lanes there? I would of thought it would be a bit tight with the existing bridges

spacetweek

roadmaster wrote: »

Would there be room to put in 2 extra lanes there? I would of thought it would be a bit tight with the existing bridges

Plenty of space - design standard back then was to have a very wide median.

roadmaster

spacetweek wrote: »

Plenty of space - design standard back then was to have a very wide median.

I stand corrected, drove the N3 today and like you say there is room. It might be a bit tight under the mulhudert interchange but you would get the lanes in, if the need ever arised you could pull 3 lanes to navan easy enough. Is there anything on the books officially for extra lanes from clonee to the M50?

ThisRegard

You couldn't get the extra lanes in at the bridge over the Blakestown Road without reenginerring or rebuilding the existing bridge which is just about wide enough for 2 lanes on each side of it.

roadmaster

ThisRegard wrote: »

You couldn't get the extra lanes in at the bridge over the Blakestown Road without reenginerring or rebuilding the existing bridge which is just about wide enough for 2 lanes on each side of it.

Is that the underpass that brings you in to Mulhudert Village?

marno21

roadmaster wrote: »

I stand corrected, drove the N3 today and like you say there is room. It might be a bit tight under the mulhudert interchange but you would get the lanes in, if the need ever arised you could pull 3 lanes to navan easy enough. Is there anything on the books officially for extra lanes from clonee to the M50?

Yes, there's a feasibility study ongoing for a widening/possible motorway upgrade from Clonee to M50

ThisRegard

roadmaster wrote: »

Is that the underpass that brings you in to Mulhudert Village?

Yeah, that's the one. There's also a similar one over the road to Blanchardstown Hospital from Blanchardstown Village, but I think that one is wider.

Kermit.de.frog

Upgrading N3/M50 to motorway could be a problem with the bus lane on the N3?

spacetweek

Kermit.de.frog wrote: »

Upgrading N3/M50 to motorway could be a problem with the bus lane on the N3?

You can have bus lanes on motorways , but the bus won't be able to stop there.

BelfastVanMan

spacetweek wrote: »

Kermit.de.frog wrote: »

Upgrading N3/M50 to motorway could be a problem with the bus lane on the N3?

You can have bus lanes on motorways , but the bus won't be able to stop there.

Indeed; in NI, they're currently putting bus lanes on both the M1 and M2 approaching Belfast.

highdef

BelfastVanMan wrote: »

Indeed; in NI, they're currently putting bus lanes on both the M1 and M2 approaching Belfast.

Would it not cause traffic issues and congestion having buses limited to 65km/h travelling on a road with a limit of 120km/h? From experience, out of service Dublin Bus buses travelling on the M4 to/from Maynooth to Dublin cause some disruption to traffic as faster moving vehicles often don't realise how slow the buses are travelling and end up stuck behind said buses because they didn't overtake in time. Quite often a queue will develop behind the bus as the vehicles are unable to get up to speed quick enough to safely overtake as cars in lane 2 are going around double the speed.

The buses presence on the motorway is completely legal however I'm just discussing the increased level of congestion and associated decrease in safety as a result.

BelfastVanMan

Well, it's a 70mph limit there, and the buses travel at 50mph, and the last few miles of the M1 near Belfast has a variable speed limit, so in fairness, it should work ok....on paper.

I agree with you that it's going to cause issues, however.

BelfastVanMan

Anyway, sorry for going off topic, folks. :-)

highdef

BelfastVanMan wrote: »

Anyway, sorry for going off topic, folks. :-)

You're grand but there's a big difference between 80km/h (50mph) and 65km/h, in terms of motorway driving.

Sam Russell

Surely regular buses on the motorway would be in a bus lane that would replace the hard shoulder.

BelfastVanMan

That's exactly the case, yes.

Sam Russell

Then the bus lane would have to be restricted to the maximum speed of the buses - so coaches or taxis keep out of it except for congested periods.

Maybe even keep them out anyway.

roadmaster

To keep a bus lane would be possible to put in 5 lanes 3 for dual, 1 for bus and 1 for breakdown by digging all the embankments right back to give extra room and build big retaining walls to keep the ground in place or would this just cost to much money to make it a viable project ?

BelfastVanMan

Yes, and probably, in that order, I fear.
:-(

riddlinrussell

roadmaster wrote: »

To keep a bus lane would be possible to put in 5 lanes 3 for dual, 1 for bus and 1 for breakdown by digging all the embankments right back to give extra room and build big retaining walls to keep the ground in place or would this just cost to much money to make it a viable project ?

Northern M1/M2 bus lanes are just taking the place of the breakdown lane, growing consensus among road planners is that full breakdown lanes are less important than they were in previous decades as cars are far less prone to breakdown. Periodic "breakdown bays" as seen in a number of European countries seems to be a potential solution.

spacetweek

BelfastVanMan wrote: »

Yes, and probably, in that order, I fear.
:-(

Are taxis allowed to drive in bus lanes in NI?

riddlinrussell

spacetweek wrote: »

BelfastVanMan wrote: »

Yes, and probably, in that order, I fear.
:-(

Are taxis allowed to drive in bus lanes in NI?

No, they've been lobbying hard for it but only buses, and disabled accessible taxis allowed. And bicycles, but obviously not on a motorway.