M11/N11 bottleneck on Fridays

doolox

I have a regular appointment in Bray at 5.30 pm and I find it takes me 1.5 hrs to get to Bray from Lucan leaving Lucan at 4.00 pm. If I leave any later I am late!!

I know that there are two main bottlenecks, one in the town from the north motorway roundabout that joins Bray to Shankill and other areas North of it. This can be explained by the ONLY crossing of the river Dargle just past the large shopping centre and the Castle motor car dealership. There is nothing that can be done about that unless Wicklow Co Co start building other bridges across the Dargle and thats not going to happen soon.

The other snarl is on the M50 which becomes a car park at 4.00pm onwards from Cherrywood ( exit 16) southwards. I have examined the maps and it seems that the M11 becomes N11 at Kilmacanogue but is still Dual Carriageway for many miles south so what causes the complete stopping one gets on the M50 at the exit 16????

I have found it faster to go through Stillorgan, exiting at exit 14, turning right at the end of Brewery Road, very little traffic and two lanes to do it in while the town bound traffic (80-90% of it ) has only one lane. then it is almost free flow all the way to the Bray North exit under taking all the "parked" cars on the m50 carpark..... what is causing all this stopping if there is dual carriageway all the way south.....similar N class roads in Athlone, for example, have 100kph limits and the n4 at Lucan has 80kph limits but you do not see the fiasco that is the m50 southbound at 4pm of Fridays......are there traffic lights in Kilmacanogue or Glen of the Downs???

punisher5112

All down to volume and lane changing and entering and exiting cars.

Rains it is 100 times worse.

There are so many exits and entrances this adds to it all.

Alun

There's a short 60km/h speed limit southbound on the N11 at Kilmacanogue, due to a ridiculous road layout at the petrol station, and an 80km/h limit for a short section of the N11 through Glen of the Downs for some reason or another that's not immediately obvious. There's also tailbacks at the Bray South exit which spill over on to the main carriageway which slows stuff down earlier anyway, and the total inability of Irish drivers to merge properly ensures the M11/M50 merge is a bottleneck too.

My wife works in Leopardstown Business Park, and these days heads up to Kilternan from the Carrickmines roundabout, turns left towards Enniskerry, and from there you can then either rejoin the motorway at the Ennsiskerry exit (requires a loop back to the Fassaroe exit to head southbound) or else there's a back route that'll bring you out at the Kilcroney roundabout instead which is what she does. Quicker and more pleasant than sitting in a traffic jam from Cherrywood onwards.

punisher5112

Glen of the downs speed of 80k was put in place because of the sharp bend and there has been quite a few serious collisions on the bend heading south. You can see the marks left behind on concrete barrier.

The north side is wider and no where near as sharp a bend so is left at 100km/h
It's also had a few offs.

Alun

punisher5112 wrote: »

Glen of the downs speed of 80k was put in place because of the sharp bend and there has been quite a few serious collisions on the bend heading south. You can see the marks left behind on concrete barrier.

The north side is wider and no where near as sharp a bend so is left at 100km/h
It's also had a few offs.

There are sharper bends than that on some of the older unrestricted autobahns in Germany. Irish motorists' predilection for either not maintaining their tyres or fitting cheap Chinese ditchfinders is a more likely cause.

steve-o

Alun wrote: »

an 80km/h limit for a short section of the N11 through Glen of the Downs for some reason or another that's not immediately obvious.

There's an entrance into the parking and picnic area. Speed limit reverts to 100 immediately after it.

loyatemu

4 lanes of traffic (2xN11 and 2xM50) merging into 2 over the space of about 2km is the issue. At busy times this causes bunching and 2 lanes isn't enough capacity there anyway.

There are plans to increase to 3 lanes as far as J7 and also add collector roads on either side so that some of the minor junctions, such as Herbert Rd southbound and Enniskerry (6a) can be closed; AFAIK there is no current timetable for this work to be done.

Alun

loyatemu wrote: »

4 lanes of traffic (2xN11 and 2xM50) merging into 2 over the space of about 2km is the issue.

In my experience the problem is that people don't merge over the available 2km, they all go into panic mode and try and merge as soon as is humanely possible even if that means crossing over the cross hatching or solid white lines.

Alun

loyatemu wrote: »

There are plans to increase to 3 lanes as far as J7 and also add collector roads on either side so that some of the minor junctions, such as Herbert Rd southbound and Enniskerry (6a) can be closed; AFAIK there is no current timetable for this work to be done.

I'm aware of those 'plans' too, but I really can't see how they think they'll be able to physically fit 3 lanes plus a collector road into the space available. It gets quite narrow there as you go past the Herbert Rd junction.

loyatemu

Alun wrote: »

In my experience the problem is that people don't merge over the available 2km, they all go into panic mode and try and merge as soon as is humanely possible even if that means crossing over the cross hatching or solid white lines.

Presumably the layout and marking of the lanes could be improved (similar to what they're doing on some of the M50 junction) but I think anywhere you have so much merging going on, there is going to be congestion. There is also the perception that drivers who stay in the sliplane are somehow trying to "jump the queue"

jobless

Alun wrote: »

There's a short 60km/h speed limit southbound on the N11 at Kilmacanogue, due to a ridiculous road layout at the petrol station, and an 80km/h limit for a short section of the N11 through Glen of the Downs for some reason or another that's not immediately obvious. There's also tailbacks at the Bray South exit which spill over on to the main carriageway which slows stuff down earlier anyway, and the total inability of Irish drivers to merge properly ensures the M11/M50 merge is a bottleneck too.

My wife works in Leopardstown Business Park, and these days heads up to Kilternan from the Carrickmines roundabout, turns left towards Enniskerry, and from there you can then either rejoin the motorway at the Ennsiskerry exit (requires a loop back to the Fassaroe exit to head southbound) or else there's a back route that'll bring you out at the Kilcroney roundabout instead which is what she does. Quicker and more pleasant than sitting in a traffic jam from Cherrywood onwards.

would you have a map for this?, especially the last part

Alun

jobless wrote: »

would you have a map for this?, especially the last part

Here you go ...

https://www.google.ie/maps/dir/53.2544333,-6.1772913/53.1841405,-6.1365646/@53.2085867,-6.1841125,13.25z/data=!4m14!4m13!1m10!3m4!1m2!1d-6.1961897!2d53.2395214!3s0x486709d1ec36c32d:0x72bee5661b34f5cd!3m4!1m2!1d-6.1730328!2d53.1971466!3s0x4867a7a8f2c8fb3f:0xc6d0d46e22fb5e41!1m0!3e0?hl=en

As you're approaching Enniskerry from the direction of Kilternan / The Scalp you have a choice where the road splits by the Texaco garage, but I prefer to keep straight and avoid the centre of Enniskerry. You come to a crossroads, go straight across and then right at the T junction, past the entrance to Powerscourt. Keep going, over the narrow bridge and then take a left where the 'main' road goes right, it's signposted to Powerscourt Waterfall to the right and there's a white cottage in front of you. Then it's another 1.7km to where you turn off left, I think there's a broken sign pointing to Enniskerry but not sure, and this brings you down on to the Kilcroney roundabout.

It's a bit confusing the first couple of times, but you soon get the hang of it.

BoatMad

punisher5112 wrote: »

Glen of the downs speed of 80k was put in place because of the sharp bend and there has been quite a few serious collisions on the bend heading south. You can see the marks left behind on concrete barrier.

The north side is wider and no where near as sharp a bend so is left at 100km/h
It's also had a few offs.

The NRA at the time confirmed that the road in the glen of the downs was built to cope with 100km.h traffic, the decision was purely wicklow Co co based on no data

BoatMad

loyatemu wrote: »

4 lanes of traffic (2xN11 and 2xM50) merging into 2 over the space of about 2km is the issue. At busy times this causes bunching and 2 lanes isn't enough capacity there anyway.

There are plans to increase to 3 lanes as far as J7 and also add collector roads on either side so that some of the minor junctions, such as Herbert Rd southbound and Enniskerry (6a) can be closed; AFAIK there is no current timetable for this work to be done.

no the delays are almost all to do with the slowdown at Kilmac. the ancillary delays are not a major contributor, take the speed upto to 120 at kilmac and the delays would melt away

BoatMad

punisher5112 wrote: »

Glen of the downs speed of 80k was put in place because of the sharp bend and there has been quite a few serious collisions on the bend heading south. You can see the marks left behind on concrete barrier.

The north side is wider and no where near as sharp a bend so is left at 100km/h
It's also had a few offs.

the glen of the downs speed limit is not a major factor in the M11 queuing before bray north , this is almost exclusively down to the crazy slowdown at Kilmac.

as a temporary fix, the merge there should be closed and traffic from the station forced up and over at the roundwood exit. ( as they have done at lucan ) , the speed limit could then be raised to 80 at least

ThisRegard

Alun wrote: »

My wife works in Leopardstown Business Park, and these days heads up to Kilternan from the Carrickmines roundabout, turns left towards Enniskerry,

It's not always quicker because when the delays are at their worse you'll get plenty of people doing that, so you can be sitting in a long queue of traffic just to get to the traffic lights at the pub to take the left to Kilternan.

Google traffic and maps will suggest that route when it's really bad, but more often than not it will tell you it's not any quicker.

BraveDonut

I recently sent an email to TII to ask about the plans for this stretch of road. My question was in light of the fact there are plans to build ~3200 housing units, etc. at Cherrywood. Here is the response that I received:



Since the completion of the upgrade of the M50 in 2011, Transport Infrastructure Ireland (TII) (formerly NRA) has been continuously monitoring traffic flow and traffic growth on the M50. As part of the upgrade of the M50 a number of traffic monitoring units have been installed which record traffic volumes, speed and journey time. In addition the day to day operation of the M50 is managed by the Maintenance Contractor and the road network is managed via the Motorway Traffic Control Centre. TII have been undertaking on-going studies at the M50 / M11 merge location and its environs. The initial studies indicated that the primary cause of PM Peak congestion in this area is related to issues with downstream junctions accessing Bray e.g. Bray North, Fassaroe, Killarney Road.



In this regard an M11/ N11 Corridor study is underway. This study is a strategic study on M/N11 corridor from its junction with the M50 to Junction 14 at Cullenmore where the M11 Motorway commences, a distance of 22km. T he N11 forms part of the Comprehensive Trans-European Transport Network.

The tasks associated with the study are as follows:
1) To identify existing deficiencies in the N11 corridor and junctions based on current traffic levels
2) To identify upgrades required to cater for current and future traffic on the N11/M11 corridor and junctions
Following development of the Improvement scheme, interim interventions will be identified for phased implementation of various measures such that benefits to the corridor can be realised at an early stage. The initial priority is to identify interventions to reduce congestion on the corridor, at junctions to the south of the M11/M50 Merge which are contributing to the long tailback on the M50 and M11 in the evening peak period.

The study team has been liaising with Dun Laoghaire-Rathdown County Council, Wicklow County Council and National Transport Authority (NTA) officials on the study. It is anticipated that finalisation of the study will take place in Q3, 2016. The Greater Dublin Area Transport Strategy (2016-2035) includes projects aimed at reducing congestion and enhancing the national road network. Capacity enhancement measure and reconfiguration of the M11/N11 from Junction 4 (M50) to Junction 14 (Ashford) has been included in the strategy.



With respect of the proposed developments at Cherrywood it should be noted that the lands at Cherrywood are covered by a Strategic Development Zone (SDZ) (Cherrywood Planning Scheme)which provides a statutory context and framework for the delivery of development. The Cherrywood Planning Scheme was developed by Dun Laoghaire Rathdown County Council and TII were a Statutory Consultee providing inputs in respect of both the national road and Luas issues at Cherrywood. For this reasons various limits have been set for the volume of development and the phasing is associated with the delivery of critical roads, public transport and demand management measures in the area.

jobless

Alun wrote: »

Here you go ...

https://www.google.ie/maps/dir/53.2544333,-6.1772913/53.1841405,-6.1365646/@53.2085867,-6.1841125,13.25z/data=!4m14!4m13!1m10!3m4!1m2!1d-6.1961897!2d53.2395214!3s0x486709d1ec36c32d:0x72bee5661b34f5cd!3m4!1m2!1d-6.1730328!2d53.1971466!3s0x4867a7a8f2c8fb3f:0xc6d0d46e22fb5e41!1m0!3e0?hl=en

As you're approaching Enniskerry from the direction of Kilternan / The Scalp you have a choice where the road splits by the Texaco garage, but I prefer to keep straight and avoid the centre of Enniskerry. You come to a crossroads, go straight across and then right at the T junction, past the entrance to Powerscourt. Keep going, over the narrow bridge and then take a left where the 'main' road goes right, it's signposted to Powerscourt Waterfall to the right and there's a white cottage in front of you. Then it's another 1.7km to where you turn off left, I think there's a broken sign pointing to Enniskerry but not sure, and this brings you down on to the Kilcroney roundabout.

It's a bit confusing the first couple of times, but you soon get the hang of it.

Thank you, ill defo try this route sometime

Macy0161

BoatMad wrote: »

the glen of the downs speed limit is not a major factor in the M11 queuing before bray north , this is almost exclusively down to the crazy slowdown at Kilmac.

as a temporary fix, the merge there should be closed and traffic from the station forced up and over at the roundwood exit. ( as they have done at lucan ) , the speed limit could then be raised to 80 at least

This does need to be done, due to the idiotic and dangerous driving that goes on in and out of the garage (drivers seem to have brain farts and/or complete ignorance at both petrol stations in Kilmac), but I think previous studies have shown the main cause of the delays is the Bray South junction for the Southbound traffic.

Also on the route through Enniskerry - it's not necessarily quicker. Glenamuck Road can be busy, and if you get stuck behind something you are goosed/ lose any time saving. I think it's more the perception of actually moving a lot of time rather than actually being much quicker.

BoatMad

BraveDonut wrote: »

I recently sent an email to TII to ask about the plans for this stretch of road. My question was in light of the fact there are plans to build ~3200 housing units, etc. at Cherrywood. Here is the response that I received:



Since the completion of the upgrade of the M50 in 2011, Transport Infrastructure Ireland (TII) (formerly NRA) has been continuously monitoring traffic flow and traffic growth on the M50. As part of the upgrade of the M50 a number of traffic monitoring units have been installed which record traffic volumes, speed and journey time. In addition the day to day operation of the M50 is managed by the Maintenance Contractor and the road network is managed via the Motorway Traffic Control Centre. TII have been undertaking on-going studies at the M50 / M11 merge location and its environs. The initial studies indicated that the primary cause of PM Peak congestion in this area is related to issues with downstream junctions accessing Bray e.g. Bray North, Fassaroe, Killarney Road.



In this regard an M11/ N11 Corridor study is underway. This study is a strategic study on M/N11 corridor from its junction with the M50 to Junction 14 at Cullenmore where the M11 Motorway commences, a distance of 22km. T he N11 forms part of the Comprehensive Trans-European Transport Network.

The tasks associated with the study are as follows:
1) To identify existing deficiencies in the N11 corridor and junctions based on current traffic levels
2) To identify upgrades required to cater for current and future traffic on the N11/M11 corridor and junctions
Following development of the Improvement scheme, interim interventions will be identified for phased implementation of various measures such that benefits to the corridor can be realised at an early stage. The initial priority is to identify interventions to reduce congestion on the corridor, at junctions to the south of the M11/M50 Merge which are contributing to the long tailback on the M50 and M11 in the evening peak period.

The study team has been liaising with Dun Laoghaire-Rathdown County Council, Wicklow County Council and National Transport Authority (NTA) officials on the study. It is anticipated that finalisation of the study will take place in Q3, 2016. The Greater Dublin Area Transport Strategy (2016-2035) includes projects aimed at reducing congestion and enhancing the national road network. Capacity enhancement measure and reconfiguration of the M11/N11 from Junction 4 (M50) to Junction 14 (Ashford) has been included in the strategy.



With respect of the proposed developments at Cherrywood it should be noted that the lands at Cherrywood are covered by a Strategic Development Zone (SDZ) (Cherrywood Planning Scheme)which provides a statutory context and framework for the delivery of development. The Cherrywood Planning Scheme was developed by Dun Laoghaire Rathdown County Council and TII were a Statutory Consultee providing inputs in respect of both the national road and Luas issues at Cherrywood. For this reasons various limits have been set for the volume of development and the phasing is associated with the delivery of critical roads, public transport and demand management measures in the area.

remember these are the successors of the people that told us the toll plazas on the M50 were not a source of congestion ........!!!!!!! ( and that the we didnt need motorway crash barriers ), how'd all that work out for them .,......

Carawaystick

I regularly get held up at the M11/M50 merge and there's no traffic at Kilmac. It's surely the 4-2 merge here? along with the really short on merge after.

jobless

Carawaystick wrote: »

I regularly get held up at the M11/M50 merge and there's no traffic at Kilmac. It's surely the 4-2 merge here? along with the really short on merge after.

I dont travel as far as Kilmac but i dont think its the main issue here.... obviously the 4 -> 2 merge causes most of it but past the point it ends the road becomes no longer a straight run... you can noticably see traffic go slower around the bend near the herbert road exit... I've even seen it back up here on quiet days.... just after the greystones exit the traffic moves quite freely again...

shar01

Here's an "out there" suggestion... Enforcement of the tailgating law and interactive speed signs.

At evening rush-hour I will sometimes go southbound through Shankill village because it's quicker and less stressful that trying to merge with the M11. The lack on consideration and general manners at the M11/M50 merge is shocking. I had a car accelerate into a gap I was merging into. If I wasn't paying attention to my rear view mirrors, she would've gone into me.

Mornings going northbound are particularly bad for the rear-ending in the right lane. From what I can see it's people driving too close and having no time to react.

I stay left, leave a decent gap between the car in front and will regularly pass a line of stopped cars in the right lane from junction 6 to Cherrywood.

BoatMad

having travelled it regularly , I remain convinced that the issue is the Kilmac slowdown and not the Bray North congestion , Th right lane typifies the issue , clearly most are not leaving the dual carriageway, yet the right lane is often the slowest and thats nearly the issue of Kilmac.

exactly the same arguments were advanced by the NRA over the toll plaza on the M50, blaming the previous junctions for the congestion , yet traffic flow significantly improved when barrier less tolling was implemented, no-one would now suggest that is was not an idea worth implementing.

restricting access from the garage unto the N11 and forcing those exiting to use the roundwood exit , just like was done at lucan, would at least allow the speed limit to be raised to 80kmph. I get the distinct feeling, have read correspondence from Wicklow Co. Co. and the NRA that Wicklow CO.co dont want any quick fix and want the NRA to stump up for a big overhaul of several junctions.

Chris_5339762

Nah its Bray North that causes the trouble. The four lane weaving section slows traffic down dramatically. Further south its also a problem, as you effectively have four lanes turning into two (ignoring the traffic leaving at Bray North).

BoatMad

Chris_5339762 wrote: »

Nah its Bray North that causes the trouble. The four lane weaving section slows traffic down dramatically. Further south its also a problem, as you effectively have four lanes turning into two (ignoring the traffic leaving at Bray North).

having travelled it regularly , I dont agree, I think there are two problems and the speed limiting is a major one

Exactly the same arguments were advanced that the toll plaza wasn't the cause of delays, yet , significant speedup was shown when the barriers were removed.

evidence shows that any speed bottleneck ripples back to cause major problems behind once the road is close to capacity

thats not to say the merge and Bray North arnt helping of course , its a perfect storm

ThisRegard

BoatMad wrote: »

having travelled it regularly , I remain convinced that the issue is the Kilmac slowdown and not the Bray North congestion

I don't think so, by the time you get near Kimac the traffic has loosened up considerably and the only thing slowing traffic at that point is the speed limit, not congestion due to the speed limit, as you can be sitting at 100kph until that point as the road clears up after the Bray exits.

BoatMad

ThisRegard wrote: »

I don't think so, by the time you get near Kimac the traffic has loosened up considerably and the only thing slowing traffic at that point is the speed limit, not congestion due to the speed limit, as you can be sitting at 100kph until that point as the road clears up after the Bray exits.

the effect of a dramatic slowdown to 60kmph ( from in effect a theoretical 120kmph) on a road that is close to capacity must and is dramatic , causing tailbacks. Its exactly the same issue as the toll plazas

Macy0161

IF it is kilmac, it's the kamikaze/ pig ignorant entry and exits into the petrol station that are the real cause rather than the speed limit in my experience. I'm still not convinced it's the real issue (I'd often be held up/ slowed down around Bray South and it be fine in Kilmac), but for sure if they sorted out the junctions it'd probably shift more of the problem to Kilmac so it does need to be addressed.

ThisRegard

BoatMad wrote: »

the effect of a dramatic slowdown to 60kmph ( from in effect a theoretical 120kmph) on a road that is close to capacity must and is dramatic , causing tailbacks. Its exactly the same issue as the toll plazas

But my point is that there's no tailbacks for a few k coming up to Kilmac.

BoatMad

ThisRegard wrote: »

But my point is that there's no tailbacks for a few k coming up to Kilmac.

huh, I disagreed , Ive sat in them , and theres less then a KM from KIlmac to bray north anyway ( not a few Kms)

loyatemu

BoatMad wrote: »

huh, I disagreed , Ive sat in them , and theres less then a KM from KIlmac to bray north anyway ( not a few Kms)

It's 5km from Bray North to the 60 limit at Kilmac:

https://goo.gl/maps/Hje7DYzLUBK2

BigMoose

I've only just found this thread and as a daily commuter from Wicklow to Parkwest I'm pleased to hear they are at least looking at the issues on this stretch of road - even if I have no faith that they'll bother to do anything. It's shocking that all involved aren't eager to implement some quick fixes at the idiotic layout at the kilmac petrol stations!

As for the Enniskerry detour, I'll do this anytime heading home I hear on Dublin City Radio that it's worse than "normal" at the M50/N11 merge - except I'll go right at the white cottage (after the narrow bridge) and come out at the Kilmac junction just after the petrol stations to rejoin the N11. Dont see the point in ending up doubling back at Fassaroe.

The hold ups are a combination of all the mentioned things, but the worst issue is the M50/N11 merge to Bray North. Every day traffic will pile up at Jn16 Cherrywood but typically starts moving again (all be it slow) once you get past Bray North. Yes it can stop start again all the way to Bray South but it's rare it stops completely again into Kilmac. Of course a crash anywhere along there and all bets are off.

OldMrBrennan83

This post has been deleted.

marno21

Patww79 wrote: »

This post has been deleted.

Widening it to 3 lanes as far as J6 would be a good start.

The Greater Dublin Area transport plan has a plan for widening of the M50 from where it currently narrows to 2 lanes, past the M11 merge as far as J6 Fassaroe. The N11 would be reconfigured to a motorway from J6 to J14 Coyne's Cross. Much needed but it will be an incredible engineering challenge to get it done.

shar01

marno21 wrote: »

Widening it to 3 lanes as far as J6 would be a good start.

The Greater Dublin Area transport plan has a plan for widening of the M50 from where it currently narrows to 2 lanes, past the M11 merge as far as J6 Fassaroe. The N11 would be reconfigured to a motorway from J6 to J14 Coyne's Cross. Much needed but it will be an incredible engineering challenge to get it done.

I honestly think poor driver behaviour plays a large part in the mess at the Merge. Tailgaters won't allow others to merge safely. I'd like to see the RSA or whoever try interactive speed limit signs - enforced with speed cameras.

OldMrBrennan83

This post has been deleted.

BigMoose

I agree that poor behavior doesn't help - people bail off the M50 onto the left lane for the M11 too early, some into the hash markings, but others leg it up the left lane and pull into the M50 at the very last minute causing that lane to stop to let them in... Then of course folk in the right lane tailgate and refuse to let anyone over.

BUT of course additional lanes would help ease the congestion. It would have to go down far enough though so that extra free flowing traffic from the merge doesn't just back up. I would think to Bray South to make any real difference (while sorting the garage, Herbert Rd and in the other direction Enniskerry). But that's a costly ask. Widening just to Fassaroe I fear wont help as it will back up as soon as it does go down to 2 before loads pile off at Bray South.

vickers209

BigMoose wrote: »

As for the Enniskerry detour, I'll do this anytime heading home I hear on Dublin City Radio that it's worse than "normal" at the M50/N11 merge - except I'll go right at the white cottage (after the narrow bridge) and come out at the Kilmac junction just after the petrol stations to rejoin the N11. Dont see the point in ending up doubling back at Fassaroe.

You don't need to double back to fassroe when you turn left at the white cottage go about 2km and after the bad bends take a left and this will bring you out at the bray south overbridge
Much quicker than going to kilmac the other way

BigMoose

I tried going left at the white cottage once and got lost or something went wrong so never tried again! Must give that a go next time Assume there's no queue getting back on at Bray South?