N40 - Cork South Ring Bandon & Sarsfield Flyovers

ardmacha

That'll go to court considering the Tunnel received substantial EU funding.

Then put the toll on the ramps leading from the interchange towards the tunnel, to pay for the interchange not the tunnel.

The Browser

Pictures of the new gantry signage please!

phatmanwc

AugustusMinimus wrote: »

So. What benefits do people see coming from this scheme.

1. Obviously enough, people travelling on the SRR or having to go through either roundabout should see huge benefits.
2. I think this will take a lot of pressure off of the Wilton Roundabout. At peak time, a lot of people would avoid the SRR and use Wilton and Bishopstown as a rat run.
3. Point 3 will like see more traffic heading from Wilton Roundabout to Sarsfield Roundabout. People will want to use the SRR more due to the flyovers.

Well, personally, I'm not sure it will make a huge difference for me. I come from West Cork if I am travelling this way, and will still have to contend with traffic lights at both roundabouts, and Wilton-bound traffic from Ballincollig Bypass. That said, I would rarely be travelling through at peak times, and this is where the main benefits will be felt for these movements, while straight-through east-west movements will obviously be a breeze now.

I realize you said 'benefits', but while I'm at it, here's a few gripes I have with the layout, as badly needed as the whole thing is:

1. Lack of a filter lane/slip lane for Wilton-bound traffic at the Sarsfield Interchange, coming from the West, which would effectively allow the roundabout to be bypassed. One is being provided for westbound traffic coming from Sarsfield Road (south), so I think this is a pity, as it would undoubtedly have improved traffic flows.

2. Tight radius of the new Sarsfield Roundabout. I realize this was probably born out of maximum beam-spans on the overpass, and overall geometrical constraints, but honestly, it's way too tight. If there's a HGV next to you, all bets are off, it's going to be taking up 2 lanes coming around the tight bends. In addition, sight lines are poor coming up to the lights on the roundabout as a result, which don't really enter the driver's field of vision until you're about to shoot out past the stop-line.

3. Removal of pedestrian/cyclist overpass. Don't think I need to say much here, it's turned into a bit of minefield for pedestrians and cyclists, which is a pity. Really should have been better provisions to this end.

Otherwise, looking forward to next month!

AugustusMinimus

Have to agree about the Sarsfield Roundabout. It is very, very tight.

On the filter lane setup. Was discussed a few pages ago. I came up with a split level solution which obviously would have cost a bit more.

spacetweek

kub wrote: »

I believe the City Council are planning on doing away with the Wilton Roundabout and replacing it with traffic lights once the flyovers are in operation. These traffic lights seem to be a virus in Cork.

Traffic light interchanges flow traffic better and take up less land. Roundabouts are a virus in Ireland!

AugustusMinimus wrote: »

In Midleton, there's a junction where there are two sets of traffic lights stacked one on top of the other. One a foot above the other. I **** you not.

Sounds like they just did that to improve visibility. The lower one is for the front car, the higher one to enable cars further back to see it? Usually it would be more than 1 foot higher though, like 2 or 3 at least.

ardmacha

Traffic light interchanges flow traffic better and take up less land. Roundabouts are a virus in Ireland!

If they are not congested, roundabouts flow better, at least some of those in Cork are in this category. As for the land, if the roundabout is already there you don't really gain any useful land by removing it.

sheff_

Roughly 40,000 people live within 2km of the Wilton road roundabout. It's a disaster for pedestrians and cyclists to get past. The sooner it's replaced the better.

It'll be interesting to see if they somehow end up changing the Sarsfield Road roundabout again a few years down to line to rectify the mess they've made of it as regards pedestrians. I think a lot of cyclists will start using the roundabout rather than the crossing given the reduced traffic levels and better markings.

AugustusMinimus

spacetweek wrote: »

Traffic light interchanges flow traffic better and take up less land. Roundabouts are a virus in Ireland!

Explain what went wrong with the traffic lights put in place outside of the Dean Rock Bar in Togher in Cork.

They removed the roundabout, put in lights and it caused traffic chaos. So much chaos in fact, they had to spend more money returning the roundabout which had cost so much to dig up in the first place.

What about the traffic chaos on the South Douglas Road each evening heading towards Douglas since the lights went up outside of Douglas Shopping Centre. Chaos which never existed before.

Traffic lights are an absolute scourge and do nothing but make traffic flow worse.

AugustusMinimus

sheff_ wrote: »

Roughly 40,000 people live within 2km of the Wilton road roundabout. It's a disaster for pedestrians and cyclists to get past. The sooner it's replaced the better.

Just put zebra crossings on each arm and be done with it. A simple solution which seems to work in most countries.

sheff_

AugustusMinimus wrote: »

Just put zebra crossings on each arm and be done with it. A simple solution which seems to work in most countries.

Makes perfect sense. People are bad enough driving that roundabout already though without adding something else for them to concentrate on.

Leonard Hofstadter

The Skehard Road/Well Road traffic lights are also an absolute disgrace. There are tailbacks now where there never was when we had a roundabout. They wasted €1 million on this, and all it has done is to make everyones' lives in that area miserable.

The Skehard Road/Church Road junction (where the SuperValu is) has been a nightmare since they got rid of the roundabout many moons ago. When they were doing some works on the traffic lights several years ago, they had to install a temporary roundabout, and guess what - the traffic flowed so much better then, too.

Admittedly in Galway, getting rid of roundabouts has had the opposite effect, but then again people in Galway simply are not capable of using roundabouts, and some of their roundabouts have five junctions on a very small roundabout, which is one of the reasons they were a failure. Roundabouts are not always the right thing, but they can be a very effective tool for ensuring a smooth traffic flow and no tailbacks.

I appreciate that for non-motorists, roundabouts can be a pain, but there is an easy (and cheap) solution for this - install zebra crossings.

Hunterbiker

The thing about roundabouts is that (to me) they work better when not used in conjunction with a high number of traffic lights.

As an aside, in some ways we're very lucky not have roundabouts like this one.

I used to use it a lot and it flows okay but it's just wrong...

AugustusMinimus

Well Road / Skehard Road lights are absolute disaster. I had never seen congestion at that roundabout before and now its terrible there twice a day. Ditto as you say outside of Scally's in Blackrock.

And that's not even the worst of it. What about 17 sets of traffic lights going through Ballincollig. Business owners are up in arms with no one going near the town centre because of them yet the council are doing nothing about it.

MrDerp

AugustusMinimus wrote: »

And that's not even the worst of it. What about 17 sets of traffic lights going through Ballincollig. Business owners are up in arms with no one going near the town centre because of them yet the council are doing nothing about it.

The council did do something though...

They put a load of traffic lights on the back road too to make you less likely to dodge the village

neddynasty

AugustusMinimus wrote: »

Well Road / Skehard Road lights are absolute disaster. I had never seen congestion at that roundabout before and now its terrible there twice a day.

I go through that junction every morning about 8.30 and I think it's actually improved. I only go from the Well Road left towards Pairc Ui Rinn and it's now faster through that junction. In general traffic lights are crap though.

spacetweek

Reports of junctions disimproving due to replacement of a roundabout with lights are pretty anecdotal.
The traffic flow in the perpendicular direction from you could be improved.
There could be an unrelated reason for the increase in congestion, such as a new shopping centre opening or something.
I agree RABs are fine when there isn't much traffic, but in congestion they perform poorly as traffic could end up backing up through the roundabout and then there is gridlock. Crossroads don't have that problem as stopping is illegal in the yellow box so the central square always remains clear.

murphym7

spacetweek wrote: »

Reports of junctions disimproving due to replacement of a roundabout with lights are pretty anecdotal.The traffic flow in the perpendicular direction from you could be improved.
There could be an unrelated reason for the increase in congestion, such as a new shopping centre opening or something.
I agree RABs are fine when there isn't much traffic, but in congestion they perform poorly as traffic could end up backing up through the roundabout and then there is gridlock. Crossroads don't have that problem as stopping is illegal in the yellow box so the central square always remains clear.

I'll share an anecdote with ya…

The Well Road/Skehard road junction is adding time to my journey every day, costing me more money in fuel while stopped at lights every day and in my opinion has added risk of injury/crash to my journey that was never there before.

So in summary, it’s costing me more money, time and adding risk of personal injury since lights were installed and the roundabout removed. It has also indirectly cost me money from my pocket in the waste of tax payers’ money it took to build it.

How is that for an anecdote?

AugustusMinimus

spacetweek wrote: »

Reports of junctions disimproving due to replacement of a roundabout with lights are pretty anecdotal.

I suppose the traffic chaos in Togher after removal of the roundabout outside of the Dean Rock Bar was anecdotal too. So anecdotal that the City council spent another €400k to put back the roundabout which had cost €400k in the first place to remove.

Its absolutely crazy that just as the USA are finally starting to accept that roundabouts are usually a better solution than at grade signalised junction in a lot of cases, that we are doing exactly the opposite. And to some awful consequences.

The traffic which will be caused in Wilton if the roundabout is removed will be colossal. It'll be like the junction outside of Mahon Point except x5.

Live at Three

Does anyone know anything more about that story about Cork ordering too many traffic lights? Where did the story come from? Sounds like something you'd hear in a Paddy Irishman joke...

dulpit

Not sure if this is the best place for this, but when I was in Singapore a few years ago, most 4-way junctions are traffic lights, but with filter lanes for cars turning left. So if you're turning right, you're in right lane, if you're going straight you're in left lane (both with lights). If turning left there's a filter lane. Traffic seemed to flow beautifully.

phatmanwc

As far as I'm aware, roundabouts are generally considered to have a higher capacity than traffic lights.

The downsides are increased landtake, meaning they're obviously not suitable for every application, and their self-regulating nature. Hence, where high traffic movements conflict with each other, flows tend to become unbalanced, i.e., if two arms of a roundabout have high traffic volumes, and one of these arms is required to give way to traffic from the other.

Hence, in these situations, traffic lights might provide better regulation of flows in lower volume applications, if used intelligently. In higher volume applications, signalized roundabouts are more appropriate, such as the BRR, SRR and Dunkettle.

I'm guessing in the case of Skehard Road/Togher that traffic volumes were high enough and sufficiently balanced that the roundabouts were a more favourable option. The roundabout at the end of the Pouladuff, by the South Ring, is another example that functions remarkably well, and where lights would be a disaster.

I have to agree on the filter movements, lived in Canada for a number of years, and right-turns are permitted on a red-light, assuming the coast is clear, which really got things flowing more smoothly overall.

SeanW

Off topic but the problem with the current setup at Wilton RAB is that it is hostile to non-motor traffic (i.e. pedestrians). When I lived around there, I usually shopped in Tesco Wilton or Dunnes Bishopstown because both have free parking and Tesco was closer than the city centre on foot. Now ... the route wasn't the friendliest for walking either - long with lots of inclines etc. but by far the worst was the Wilton RAB. It's great for cars, but the provisions for pedestrians etc is literally non-existant, though the worn down paths in the grasses suggest people are walking it out of absolute necessity. That situation requires corrections, but I think it could be done by altering the current roundabout, to partly signalise it. By that I mean have lights that show green (on straight roads) or flashing yellow-arrow (for roundabout approaches) that only change to red when a pedestrian needs to cross. something like this:

DerMutt

Westbound signs have gone up on the overhead gantries. N22 Tralee with arrows for three lanes over the Sarsfield Road flyover bridge. Is it that wide? It doesn't look it from the road.

blindsider

Thought the same DM - doesn't look wide enough, but I'm presuming it is - the Kinsale Rd Flyover is 3 lanes east- and 2 lanes west-bound - would it make sense for this to continue as 3 lanes westbound for the new sections?

Looking good now - they do seem to be making progress. I wonder when they'll announce the opening date?

moyners

blindsider wrote: »

Thought the same DM - doesn't look wide enough, but I'm presuming it is - the Kinsale Rd Flyover is 3 lanes east- and 2 lanes west-bound - would it make sense for this to continue as 3 lanes westbound for the new sections?

Looking good now - they do seem to be making progress. I wonder when they'll announce the opening date?

There is actually space for three lanes westbound on the Kinsale Rd Flyover but they have an extra wide hard shoulder. I'm not sure of the reason, I always assumed it was because of the filtering lanes just after the flyover coming from the airport road. It'll be interesting to see what lane layout they use after the new sarsfield flyover westbound

phatmanwc

Not much progress to be seen over the past 3 or 4 days. One gantry sign on the westbound carriageway between the two intersections remained to be installed. Otherwise, the concrete parapets and noise barriers are maybe just over 50 % complete on the SR Interchange. A lot of surfacing works needed in this area also.

I'm thinking end of July at a stretch, should be interesting to see how much activity gears up over the next few weeks!

phatmanwc

DerMutt wrote: »

Westbound signs have gone up on the overhead gantries. N22 Tralee with arrows for three lanes over the Sarsfield Road flyover bridge. Is it that wide? It doesn't look it from the road.

The carriageway will be 10.5m according to the scheme drawings, which would suggest 3 lanes of 3.5m each. Even though the actual lanes aren't shown on the attached, note that this refers to the driving suface, and that there will be no hard shoulder, so it can be assumed that it will similar to the westbound side of the KR Interchange.

phatmanwc

Latest Progress Update:

The main works focus over the coming weeks will continue to be in the Sarsfield Road flyover area. Surfacing works, lighting works, erection of sound barriers etc are all being progressed and the rate of progress should be readily apparent to passing motorists as these elements of the works head towards completion.

In addition to the Sarsfield Road area, the final surfacing layer at the Bandon Road flyover will be progressed from today, 28th June 2013. This final surfacing and road lining should be completed by Friday 5th July 2013.

It is still hoped that traffic can be directed onto both flyovers before the end of July 2013. This will in turn allow further ground stabilisation works required in the area near the Headlands Apartments and also at the southern side of the Sarsfield Road Roundabout circulating carriageway to get underway. Works in both of these areas will in themselves require significant traffic management measures and details under this heading will be circulated well in advance of the works themselves. It is anticipated that these post flyover opening works will get underway in August 2013.

As always, those with queries or concerns in relation to any aspect of the scheme can contact us on 021-4969280 or 021-4965830 during working hours or on the freephone helpline number 1800 932 046, or by email on n25@ccc-site.com.

AugustusMinimus

Excellent to hear.

I'm guessing these post finishing works won't affect the mainline anyways. Traffic disruption shouldn't be too bad.

Went through Sarsfield's Roundabout last night though. First time I've driven along side an artic. The roundabout at both ends is simply too tight. Will have to be changed I'd imagine.

phatmanwc

AugustusMinimus wrote: »

Excellent to hear.

I'm guessing these post finishing works won't affect the mainline anyways. Traffic disruption shouldn't be too bad.

Went through Sarsfield's Roundabout last night though. First time I've driven along side an artic. The roundabout at both ends is simply too tight. Will have to be changed I'd imagine.

Yeah, I'd imagine the ground stabilisation works will just be on the diverge slip road, so shouldn't affect things too much. I'm assuming this will involve piling/anchoring works?

In terms of the surfacing works, I wonder if it's planned to re-surface the eastbound off-line carriageway between the two roundabouts, which formed part of the original roadway. Something tells me maybe not, since it's not in bad condition, although I could see this deteriorating pretty quickly, since it's the original 1995 surface, unless I'm mistaken? Will have to wait and see I suppose.

Otherwise, yup, the Sarsfield's Roundabout makes me shake my head every time I drive through! Must try to figure out what radius they used, and reference the DMRB