Bodkin / Headford Road roundabout replacement [Lights are on!]

antoobrien

ballinadog wrote: »

Goin back to your comment about cyclists being less important than motorists, with this design the opposite would hold true. considering that 40,000 vehicles cross this junction every day compared to I'd say 1000 cyclists (not sure on that fig but I'd be willing to bet it covers the actual figure), the cyclist has far more than his fair share of road space...

The surveys done as part of the design indicate that that guess would be a good guess for the numbers of cyclists and pedestrians using the junction.

holly8

Eeden wrote: »

I think it might be a bit unfair to call them stupid. The old slip road that was there was suicide. You had to turn your head around nearly 180 degrees to see if it was safe to continue. People remember that, so I'd say it's still ingrained in folks not to use it. No doubt it won't take long to get the message.

Yeah, I hated that old slip road. Totalled my car on it one evening when jeep with large towbar braked suddenly in front of me one evening ... and that was being really really careful ... never used it since.

galwaycyclist

ballinadog wrote: »

That'd be sound if there was an infinite amount of road space, unfortunately there ain't. They have provided a bike lane for people turning left which is isn't held up any longer than the motorists, they have provided a straight ahead bike lane which also isn't held up any longer than the motorists and they have provided the means for a cyclist to safely turn right via the use of two cycle lanes which requires the cyclist to pause for a minute. IMO the cyclist has done very well out of this new arrangement. Goin back to your comment about cyclists being less important than motorists, with this design the opposite would hold true. considering that 40,000 vehicles cross this junction every day compared to I'd say 1000 cyclists (not sure on that fig but I'd be willing to bet it covers the actual figure), the cyclist has far more than his fair share of road space...

In terms of road space the cycle lanes look to be below the required 2m width - this will need to be checked independently. However, junction capacity is about more than just "road space" it is also about how time is allocated. You explore this yourself in this post.

ballinadog wrote: »

The whole idea of these type of lights is that there is underground sensor loops that keep track of the volumes of traffic in each lane and therefore varies the sequencing depending on demand. Not only that but each junctions lights communicate with the next set down the line by using exit sensor loops. This means that the next junction has a fair idea of what volume of traffic is coming its direction and so can begin to alter its sequencing. (The reason I say "fair idea" is because there are unknown unlogged traffic emerging from housing estates, one off housing etc). So to sum up, the bodkin junction will work to an extent (it will be able to vary sequencing depending on traffic volumes in each lane)

One key issue that will now have to be established is "are there any sensor loops in the cycle lanes or in the go-left-to-turn-right boxes?".

If there are none and there are no supplementary detectors for cyclists then, in the first instance, that would immediately raise questions as to the professional competence of those who installed the traffic signals. These questions might be "deflectable" on to the people who provided the design but the questions would remain.

If it turns out that this is a traffic light system that does not respond to the presence of cyclists then that would suggest that, at off-peak times, junction capacity or "level of service" has been removed from cyclists by comparison with other systems such as those based on timers. This is because at off-peak times there will be few cars to trigger the lights on some arms so waiting cyclists might be left facing red lights that will not change.

There is an established pattern in this city of road engineers training cyclists to ignore red traffic lights. It would be regrettable if we were to see the same thing repeated here.

snubbleste

galwaycyclist wrote: »

One key issue that will now have to be established is "are there any sensor loops in the cycle lanes or in the go-left-to-turn-right boxes?".

What do you think?!

galwaycyclist

snubbleste wrote: »

What do you think?!

I wouldnt have asked the question if there were not already some unfortunate examples of incompetent traffic signal installations at other locations in the city. But we will have to establish the facts ourselves first.

Another question to be established will be are the sensor loops in the main traffic lanes tuned to detect cyclists?. Some cyclists will expect to turn right from the main lane as normal. (The go-left-to-turn right idea is not common, or commonly understood, in this country)

biko

Drove through it today for the time time as a proper intersection as the RB centre is gone.
I wasn't going fast but it felt like the now opened space wasn't perfectly flat?

ballinadog

galwaycyclist wrote: »

In terms of road space the cycle lanes look to be below the required 2m width - this will need to be checked independently. However, junction capacity is about more than just "road space" it is also about how time is allocated. You explore this yourself in this post.



One key issue that will now have to be established is "are there any sensor loops in the cycle lanes or in the go-left-to-turn-right boxes?".

If there are none and there are no supplementary detectors for cyclists then, in the first instance, that would immediately raise questions as to the professional competence of those who installed the traffic signals. These questions might be "deflectable" on to the people who provided the design but the questions would remain.

If it turns out that this is a traffic light system that does not respond to the presence of cyclists then that would suggest that, at off-peak times, junction capacity or "level of service" has been removed from cyclists by comparison with other systems such as those based on timers. This is because at off-peak times there will be few cars to trigger the lights on some arms so waiting cyclists might be left facing red lights that will not change.

There is an established pattern in this city of road engineers training cyclists to ignore red traffic lights. It would be regrettable if we were to see the same thing repeated here.

There is no sensor loops under cycle lanes simply because of the weight issue however all arms have max/min green times so if for arguments sake say the junction was deserted, as far as I know, worse case scenario, lights run to the max green time on the n6 and then revert to min green times on the other legs. Therefore this negates the issue of a cyclist having to wait for a motorist to trigger his/her arm to get a green light and before you ask the min green time is adequate for a cyclist to navigate the junction...

ballinadog

biko wrote: »

Drove through it today for the time time as a proper intersection as the RB centre is gone.
I wasn't going fast but it felt like the now opened space wasn't perfectly flat?

Perfectly flat = rain water not able to flow away = floods

joeKel73

antoobrien wrote: »

Not quite true, the left turn lane crosses the cycle lane, then there's a traffic Island to the cyclists left (at this point they are in the bus/cycle lane). So there's no traffic left of the cyclist for them to interact with.

It would be true if we were talking about coming from woodquay (which is not the question I answered).



I would have thought that goes without saying.

I think we have our wires crossed.... I'm talking about the cycle lane being not left-most on the Sean Mulvoy -> Bridge.

Which question were you answering here? I thought it was in response to the bold bit.

antoobrien wrote: »

J o e wrote: »

You pull into the cyclist turning box in front of the traffic waiting to come off the Sean Mulvoy Rd. Then when that traffic gets the green light, proceed straight over to the bridge.

http://omg.wthax.org/725zHn.png

From looking at the plans I don't see why you'd sit in the box though rather than moving directly into the cycle lane. Will be cycling this route tonight and will check it out.

Very simple, straight on traffic will be to your right as the cycle lane is the leftmost lane on the road. It'll be hard to cross it unless you hit the line while traffic is stationary (much easier to get around them).

what_traffic

ballinadog wrote: »

There is no sensor loops under cycle lanes simply because of the weight issue however all arms have max/min green times so if for arguments sake say the junction was deserted, as far as I know, worse case scenario, lights run to the max green time on the n6 and then revert to min green times on the other legs. Therefore this negates the issue of a cyclist having to wait for a motorist to trigger his/her arm to get a green light and before you ask the min green time is adequate for a cyclist to navigate the junction...

Based on other similar junctions in the city - I do not believe you. I once timed it and was waiting 8 minutes one night(23h15) for the light to trigger and that was because eventually a car came along.
Also it's not a weight issue - its a magnetic issue? Can trigger loops if one lies the bike on the ground above the loop

antoobrien

galwaycyclist wrote: »

Another question to be established will be are the sensor loops in the main traffic lanes tuned to detect cyclists?. Some cyclists will expect to turn right from the main lane as normal. (The go-left-to-turn right idea is not common, or commonly understood, in this country)

I doubt it, but then again they don't need to be based on some observations:
1) I've sat at the other three junctions wondering why the lights are red with no traffic on any of the other approaches waiting for the lights to cycle around, so it appears that the so called intelligent lights can't skip any steps - it would seem directly because of the hook turn boxes.
2) The lights on the former roundabouts are set with a minimum green time, regardless of the presence of vehicles/bikes
3) The lights on the former roundabouts are timed to let cyclists safely finish crossing the junction(s) before a the next green sequence is activated.
4) Most cyclists don't wait behind the white line, so they wouldn't trigger the sensor (oops).

So tuning the additional sensors for cyclists seems like an unnecessary step.

galwaycyclist

ballinadog wrote: »

There is no sensor loops under cycle lanes simply because of the weight issue however all arms have max/min green times so if for arguments sake say the junction was deserted, as far as I know, worse case scenario, lights run to the max green time on the n6 and then revert to min green times on the other legs. Therefore this negates the issue of a cyclist having to wait for a motorist to trigger his/her arm to get a green light and before you ask the min green time is adequate for a cyclist to navigate the junction...

Your response appears to deal with some of the issues raised. However your response is problematic because normal sensor loops are based on detecting a metal object passing through an induction loop.

The sensor loops are not based on "weight" - you should be able to trigger the sensor with a crushed coke can.

what_traffic

antoobrien wrote: »

I doubt it, but then again they don't need to be based on some observations:
1) I've sat at the other three junctions wondering why the lights are red with no traffic on any of the other approaches waiting for the lights to cycle around, so it appears that the so called intelligent lights can't skip any steps - it would seem directly because of the hook turn boxes.
2) The lights on the former roundabouts are set with a minimum green time, regardless of the presence of vehicles/bikes
3) The lights on the former roundabouts are timed to let cyclists safely finish crossing the junction(s) before a the next green sequence is activated.
4) Most cyclists don't wait behind the white line, so they wouldn't trigger the sensor (oops).

So tuning the additional sensors for cyclists seems like an unnecessary step.

Not true. Briarhill junction does not behave like this. Cycling home on lateshift from Parkmore the only way to trigger the lights if no cars are around is to lay the bike flat and directly over the loop (which is not in the cycle lane)

antoobrien

J o e wrote: »

I think we have our wires crossed

Definately.

J o e wrote: »

I'm talking about the cycle lane being not left-most on the Sean Mulvoy -> Bridge.

Which question were you answering here? I thought it was in response to the bold bit.

This one:

snubbleste wrote: »

If I'm on the cycle lane at Dunnes Terryland and wish to cross the bridge, how do I do that

antoobrien

what_traffic wrote: »

Not true. Briarhill junction does not behave like this.

It does. The sensors get mucked up in the wet (the ones for the right turn from the Monivea Rd to Parkmore Rd often don't pick up cars when its wet), but yes it does work exactly that way. So do the other two.

joeKel73

antoobrien wrote: »

Definately.

This one:

Ah, since you quoted me I thought it was in reply to me!

what_traffic

antoobrien wrote: »

It does. The sensors get mucked up in the wet (the ones for the right turn from the Monivea Rd to Parkmore Rd often don't pick up cars when its wet), but yes it does work exactly that way. So do the other two.

Luckily for Galway City then that we dont get much rain

irisheddie85

what_traffic wrote: »

Not true. Briarhill junction does not behave like this. Cycling home on lateshift from Parkmore the only way to trigger the lights if no cars are around is to lay the bike flat and directly over the loop (which is not in the cycle lane)

I havent cylcled through that junction but I have driven through and even when there are no other cars or cyclists on any arms you have to wait for the lights to go through all sequences to get to where you are. The lights don't suddenly skip part of the sequence just because there is a car on one Road and not another.

The only way that could be really implemented would be if when it detected no traffic on any legs all lights were red but as soon as a sensor was tripped that light turned Green. And this clearly isn't what happens

ballinadog

galwaycyclist wrote: »

Your response appears to deal with some of the issues raised. However your response is problematic because normal sensor loops are based on detecting a metal object passing through an induction loop.

The sensor loops are not based on "weight" - you should be able to trigger the sensor with a crushed coke can.

Your right about the metal object and the induction loop however I am also correct when I declared weight being an issue (there is various loop types, ones that pick up only buses and not cars etc, where weight is an issue)... Lads I'd love to have been on here years ago when there was no such thing as bike lanes at all. Like what are ye complaining about exactly? Cannot deny that the level of service at this junction is greatly improved on the roundabout? And to me, the greatest contributor to the Term Level of Service would be safety? Why are ye letting it bother ye so much that if you want to turn right at this junction you have have to wait a min/90 secs in a cycle hook? Either way it's a lot quicker than dismounting the bike and walking it through the pedestrian crossings which one had to do under the old regime to navigate the junction safely

finlma

biko wrote: »

Drove through it today for the time time as a proper intersection as the RB centre is gone.
I wasn't going fast but it felt like the now opened space wasn't perfectly flat?

You're dead right. There's a big bump in the middle of the junction. I came over it today.

what_traffic

ballinadog wrote: »

Your right about the metal object and the induction loop however I am also correct when I declared weight being an issue (there is various loop types, ones that pick up only buses and not cars etc, where weight is an issue)...

So which one is being used here?

ballinadog

what_traffic wrote: »

So which one is being used here?

Haven't a clue tbh, not my baby, look at my post, I didn't say you were wrong, I just indicated I wasn't wrong either

galwaycyclist

ballinadog wrote: »

junction is greatly improved on the roundabout? And to me, the greatest contributor to the Term Level of Service would be safety?

No level of service usually focuses on things like delay, green time etc. Safety is usually defined as secondary to level of service - you define the level of service first and then work to achieve the best level of safety for that level of service.

The issue is that there are other traffic light junctions around the city that were either incompetently designed or incompetently installed or both.

That is to say there are junctions around the city where various arms will not change for cyclists alone. Some that I have experience of are turning right into Rahoon Rd towards the cemetery from the Seamus Quirke Rd, turning right from the Ballybrit industrial estate towards the Tuam Rd, turning from the Fr. Griffin Avenue onto Fr Griffin Rd. etc etc etc.

We are trying to establish if these lights have also been incompetently designed or incompetently installed.

If there are no sensor loops in the cycle lanes or in the go-left-to-turn right boxes then this would tend to reinforce the expectation that this junction has not been properly constructed.

Your claim that there will be timers will have to be independently verified. Clearly by your own admission the required sensor loops have not been provided.

what_traffic

galwaycyclist wrote: »

Clearly by your own admission the required sensor loops have not been provided.

Pardon the pun - but I think ballinadog has backpeddaled on this claim. Further muddying the water - which is a requirement according to antoobrien to NOT trigger said sensor loops.

ballinadog

galwaycyclist wrote: »

No level of service usually focuses on things like delay, green time etc. Safety is usually defined as secondary to level of service - you define the level of service first and then work to achieve the best level of safety for that level of service.

The issue is that there are other traffic light junctions around the city that were either incompetently designed or incompetently installed or both.

That is to say there are junctions around the city where various arms will not change for cyclists alone. Some that I have experience of are turning right into Rahoon Rd towards the cemetery from the Seamus Quirke Rd, turning right from the Ballybrit industrial estate towards the Tuam Rd, turning from the Fr. Griffin Avenue onto Fr Griffin Rd. etc etc etc.

We are trying to establish if these lights have also been incompetently designed or incompetently installed.

If there are no sensor loops in the cycle lanes or in the go-left-to-turn right boxes then this would tend to reinforce the expectation that this junction has not been properly constructed.

Your claim that there will be timers will have to be independently verified. Clearly by your own admission the required sensor loops have not been provided.

Hang on second now before I lose the rag altogether, have you any idea of how contracts in the construction industry work? Esp since the new form of contract has been brought in?

thesandeman

I'm neither a driver or cyclist nor have I had to negotiate the new layout on foot yet, but I have to say fair play to ballinadog for answering all the points put honestly and to the best of his ability over the last couple of weeks.
If we were asking an official representative of the NRA or the council these questions can you imagine the rubbish that would be spouted in reply.

Iwannahurl

El_Dangeroso wrote: »

As an aside on this point, wasn't there a thread a while back where they directly asked the road safety authority about the kirwan roundabout particularly and they were unable to give a straight answer on the number of exits vs. degrees debate?

Can't find the thread in question but did find this thread:
http://www.boards.ie/vbulletin/showthread.php?p=70800690

When you see someone referring to the number of exits you know they're not up to date regarding the use of (Irish) roundabouts.

The RSA issued a leaflet on the subject a couple of years ago (following a bit of pressure, I reckon) so no excuses any more.

http://www.rsa.ie/Documents/Road%20Safety/Leaflets/Leaf_booklets/Roundabouts_DL_2012_v3.pdf

This might be the Boards thread you had in mind: http://www.boards.ie/vbulletin/showthread.php?t=2056163797&page=48

ballinadog

thesandeman wrote: »

I'm neither a driver or pedestrian nor have I had to negotiate the new layout on foot yet, but I have to say fair play to ballinadog for answering all the points put honestly and to the best of his ability over the last couple of weeks.
If we were asking an official representative of the NRA or the council these questions can you imagine the rubbish that would be spouted in reply.

Cheers, tbh I was just thinking the same thing, should just leave ye to it, ye can go and lay your bikes on the flat at the loops for all I care!

what_traffic

ballinadog wrote: »

Cheers, tbh I was just thinking the same thing, should just leave ye to it, ye can go and lay your bikes on the flat at the loops for all I care!

And then you ruin the complement by saying something like this

ballinadog

what_traffic wrote: »

And then you ruin the complement by saying something like this

Sarcasm lad