Green for pedestrians

[Herned]

Near my house is a narrow side street which is one-way, and it is signal-controlled onto the main road (here in Taunton). The lights are red for the side road ~95% of the time.

There are pedestrian signals for people walking along the main road, but is there any reason why there can't just be a green man showing for pedestrians all the time, except when the side road traffic gets it's turn? I have looked in the Manual for Streets and I can't see anything about this. It's more of an academic question really, as I don't think I have ever seen anyone press the button and wait for the lights

[traffic-light-man]

I'm assuming when the button is pressed, they do run with the main road, and it's not that it stops all traffic while the peds run?

There's no technical reason why they can't be green with the main road all the time, and I think it'd be normal to have them like that. But, having said that, if they'd be showing a green man for most of the time, they may be configured to only show when demanded (or similar) to stop the rotating tactile cones from burning out. There's other ways around that problem, but this is one solution.

I've seen it done on large low-ped, high-vehicle sites where minimum greens and intergreens associated with peds are towards the higher end, and so running them every cycle reduces the efficiency, but I really can't see that being a reason in this case!

There's a few different parameters that can be set that affects when they're allowed to run and how they run, but most of the ones I've come across that are 'only show when demanded' will show a green man as soon as you press the button, as long as a stage that they're part of is running.

[jnty]

I've seen this for two-way side roads where a banned turn would permit a pedestrian phase to run alongside an adjacent traffic movement but presumably there isn't enough trust that compliance will be sufficient to guarantee a suitable level of pedestrian safety.

That seems like less of a risk here given that it's one way, but perhaps there's a feeling that people still might make risky mistakes, particularly given the tight geometry - by the time you realise when turning left you might already be fully over the crossing.

The other thing I can think of is that a pedestrian green would presumably mean a longer delay in allowing traffic detected on the side road a green? But that seems like a poor excuse.

[Herned]

I'm assuming when the button is pressed, they do run with the main road, and it's not that it stops all traffic while the peds run?

There's no technical reason why they can't be green with the main road all the time, and I think it'd be normal to have them like that. But, having said that, if they'd be showing a green man for most of the time, they may be configured to only show when demanded (or similar) to stop the rotating tactile cones from burning out. There's other ways around that problem, but this is one solution.

I've seen it done on large low-ped, high-vehicle sites where minimum greens and intergreens associated with peds are towards the higher end, and so running them every cycle reduces the efficiency, but I really can't see that being a reason in this case!

There's a few different parameters that can be set that affects when they're allowed to run and how they run, but most of the ones I've come across that are 'only show when demanded' will show a green man as soon as you press the button, as long as a stage that they're part of is running.

There isn't a pedestrian crossing across the main road (which is a different matter), so it wouldn't stop the traffic. As I said I don't think I have ever seen anyone press the button. I will do it next time I'm there and see what happens.

The tactile cones thing is possible, but in general pedestrian crossings default to red rather than green, which strikes me as a systemic thing rather than because of one of the components

[Nathan_A_RF]

I've seen many cases in Southampton where pedestrian crossings stay on red when there are no vehicle movements across them. Pointless phasing is all I see. If the crossing can be green, make it green.

[L.J.D]

This set does it and always has run green man's while the main road is moving. There was also one in Wakefield too with signs warning of the possibility of illegally turning vehicles. The newer set run the same also but without the signs.

[AlexBr967]

I've noticed this at a few junctions where the button must be pressed for the signal to go green. To me, it appears to be like this in order to possibly speed things up when there is limited traffic. For example, when the junction will only trigger some directions with a sensor then the transition to those directions would be sped up by the lack of pedestrian stages needing to be finished. I think it's also so the timings can be more variable in response to traffic levels. That's my headcanon anyway.

This junction stays red unless the button is pressed even though it could be green while the main road has green

[traffic-light-man]

Here's three from three different cities where they run the green man with the main road, and revert to the main road: Liverpool, Lancaster, Manchester, and there's plenty more where those came from. I think it's normal to do that, which is why I was slightly perplexed by the original example and struggling to see a reason for it, especially given the ped timings have got to be fairly low for that tiny street.

The Liverpool (I think) and Lancaster examples have conditioning that switches the tactile cones off after a preset time if the stage hasn't come to a natural end. Any button press restarts the tactile cones until the timer expires again or the stage ends. That's what I was getting at in my earlier post where I mentioned there being other ways to prevent that problem other than having them only show when demanded.

Interestingly, the ones I can think of off the top of my head that only show when demanded and then terminate as soon as the minimum has ran are earlier MOVA sites, but that's not to say it isn't still done and in fact some areas might want this done as a standard. AlexBr967 is correct in that it one way to try and increase the efficiency by not running all the timings associated by pedestrian phases (particularly if there's on-crossings) if they're not needed, especially where the timings are high in comparison to the concurrent traffic phases.

[Herned]

Thanks for the examples, those are really suseful. I shall contact the council and see what they have to say about it

[jnty]

I've noticed this at a few junctions where the button must be pressed for the signal to go green. To me, it appears to be like this in order to possibly speed things up when there is limited traffic. For example, when the junction will only trigger some directions with a sensor then the transition to those directions would be sped up by the lack of pedestrian stages needing to be finished. I think it's also so the timings can be more variable in response to traffic levels. That's my headcanon anyway.

This junction stays red unless the button is pressed even though it could be green while the main road has green

I agree although I struggle to think of a situation where this would actually make sense - if it's not busy for cars, the timings don't matter really, and if it is busy for cars then it's probably busy for people too. Of course, when it's busy with people the button often isn't pressed as everyone assumes someone else has done it (or that the crossing will go automatically...as it should.)

[traffic-light-man]

I agree although I struggle to think of a situation where this would actually make sense

If you've got a traffic phase with a minimum green of 7 seconds, followed by a 5 second intergreen, but a pedestrian phase that runs at the same time has a minimum green of 9 seconds and a following intergreen of say 11 seconds, then running the pedestrian phase will add significantly more time to the cycle. I know that's a bit simplistic, but I think it illustrates the point.

Another way to do it is to have the pedestrian phase only run for its minimum, so it'll always show at the start of every stage where it runs, but it will also also terminate at its minimum so that the intergreens are running while the vehicle phases are still extending. This site works like this, but it results in the pedestrian signals changing from red to green three or four times a cycle without any conflicting vehicle movements happening. If the vehicle phases aren't extended, it will sometimes show a red for about a second before going back to green as the next stage starts.

if it is busy for cars then it's probably busy for people too.

That's a bit of a bold statement. I can think of many sites with pedestrian facilities that see huge vehicular flows and very few pedestrians.

[jnty]

I agree although I struggle to think of a situation where this would actually make sense

If you've got a traffic phase with a minimum green of 7 seconds, followed by a 5 second intergreen, but a pedestrian phase that runs at the same time has a minimum green of 9 seconds and a following intergreen of say 11 seconds, then running the pedestrian phase will add significantly more time to the cycle. I know that's a bit simplistic, but I think it illustrates the point.

But surely it would only be running to these kind of tight timings off-peak, at which point you're talking about an extra 9 seconds of delay for individual waiting motorists rather than any catastrophic capacity loss. In any case it's quite normal to be waiting at a junction and get that kind of green time given to roads with no cars on them, so I don't really see why pedestrians should be treated any differently.

if it is busy for cars then it's probably busy for people too.

That's a bit of a bold statement. I can think of many sites with pedestrian facilities that see huge vehicular flows and very few pedestrians.

The increasing prevalence of NMU provision at strategic junctions does indeed skew this but I think this would be largely true for many of the examples highlighted here.

[Debaser]

Didn't Kingston upon Hull do the whole 'resting on pedestrian green' back in the mid-nineties? It was only when a queue length of a certain number of cars was detected that they got green.

See paragraph 6.3.1.7 of this document https://content.tfl.gov.uk/factors-infl ... review.pdf

[traffic-light-man]

But surely it would only be running to these kind of tight timings off-peak, at which point you're talking about an extra 9 seconds of delay for individual waiting motorists rather than any catastrophic capacity loss. In any case it's quite normal to be waiting at a junction and get that kind of green time given to roads with no cars on them, so I don't really see why pedestrians should be treated any differently.

Maybe the inclusion of minimum timings clouded that example, but the same theory still stands, particularly for the intergreen period. Even if you do take the minimums into account, say you've got three approaches that are struggling, but a pair of right turns that will run near a minimum, that 9 seconds could make a huge difference. I've seen this loads of times, and in some places the pedestrian phases running to the same length as the traffic phases makes sense because it's in an urban environment, but in other places which might see one pedestrian per hour who typically don't even wait for the green man, I'm not sure it's such a massive problem gaining a bit of efficiency and capacity back by having the signals only show green if demanded. It's all subjective based on the site, the flows of all users and its mode of operation, though.

Didn't Kingston upon Hull do the whole 'resting on pedestrian green' back in the mid-nineties? It was only when a queue length of a certain number of cars was detected that they got green.

I think this was discussed not too long ago when TfL said they were going to try it out. There's been a set that do this in Liverpool One bus station since about 2008.

I believe Leeds have recently started with these as well.

[L.J.D]

I believe Leeds have recently started with these as well.

Leeds have also made it so the push button doesn't have to be pushed anymore they have detection equipment now that automatically activates the request. Though the option of pushing the button is still there.

[traffic-light-man]

Leeds have also made it so the push button doesn't have to be pushed anymore they have detection equipment now that automatically activates the request. Though the option of pushing the button is still there.

I didn't know they were doing that as well, that's another step forward in my book! In theory, any kerbside detector can place a demand if the controller is set up to do so. I know as part of the Covid response, some places did this (I think Southampton were one), but a lot of authorities seem to have gone for the 'wave your hand under the button' equipment which I'm not particularly a fan of. I'd much rather use a bit of kit that, in a lot of cases, is already there.

Leeds are doing some clever stuff with MOVA on ped crossings, too, where a variety of timings are varied based on the level of demand from all users. It requires a lot more thought than your typical urban Puffin fitted with MVDs, but it's the way things should be going when the technology is available to support it.