Discriminatory timing on traffic lights

[ian]

The explanation I've heard for the delay is that if the lights responded instantly to the button, people would get used to it and just cross immediately (well, say 3 seconds after) pressing the button, without checking. I reckon this is bullshit.

Seems a tad, erm, unlikely.

I suspect the explanation is more likely that drivers might be upset if they felt they were being compelled to immediately cede priority to pedestrians at crossings. Another case of balancing the needs of all road users to avoid upsetting drivers.

[Cudzoziemiec]

It's counterproductive though. It means that people get in the habit of pressing the button then looking. Arrive at crossing, press button, look. Oh, no traffic, let's cross. Thirty seconds later the lights change and hold up the traffic that wasn't there earlier for the pedestrians who have already gone. Which probably also leads to more people ignoring pedestrian crossing lights while driving.

[Jaded]

The explanation I've heard for the delay is that if the lights responded instantly to the button, people would get used to it and just cross immediately (well, say 3 seconds after) pressing the button, without checking. I reckon this is bullshit.

Seems a tad, erm, unlikely.

I suspect the explanation is more likely that drivers might be upset if they felt they were being compelled to immediately cede priority to pedestrians at crossings. Another case of balancing the needs of all road users to avoid upsetting drivers.

I thought it was because you can't possibly expect a driver to suddenly slow down if the lights change...

[Kim]

It's counterproductive though. It means that people get in the habit of pressing the button then looking. Arrive at crossing, press button, look. Oh, no traffic, let's cross. Thirty seconds later the lights change and hold up the traffic that wasn't there earlier for the pedestrians who have already gone. Which probably also leads to more people ignoring pedestrian crossing lights while driving.

Engineered around somewhat by the Puffin crossing...

[Cudzoziemiec]

The ones that use sensors to detect people waiting to cross or on the crossing? Yes. Sometimes they totally fail to detect people there even when they've pressed the button. But they still don't change instantly even when there's no traffic.

[ian]

And what, for that matter, is with the crossings that mount the crossing indicator on the pole next to you rather than ahead on the other side of the road. Which means you have to watch the indicator, and not the road or traffic. Seems stunningly stupid. I presume an idea from people who have never crossed a road.

[trekker12]

There is a set of those on a busy four way crossing near my home. I swear the button is a complete placebo (I'm sure I heard an expert on the radio once confirm some of them are).

The button and light arrangement are on the post for the cars heading parallel to me from the other side of the crossing, a foot behind where I'm standing waiting to cross so I can't see it and then it doesn't even beep.

What the hell is a blind person supposed to do with it?

[Kim]

There are a series of toucan crossings on Birmingham's Token Decent Cycle Route, and a pelican on Silly Oak High Street which do change instantly (or at least within a couple of seconds) some of the time.  They'll make you wait if they've just changed, and will make you wait under other circumstances too (presumably related to the amount of road traffic).  I think the high street one detects emergency vehicles and stays green, which makes sense as it's on a route between the hospital and the site of a fire and former ambulance station.

Stands to reason that the zillions of traffic lights around the country aren't all programmed the same way - indeed, they're probably running on completely different software and hardware from more than one manufacturer with different default "bog standard pelican crossing" settings even if they haven't been individually tweaked.  You can't really predict the behaviour of a given crossing until you're familiar with it.

[Kim]

And what, for that matter, is with the crossings that mount the crossing indicator on the pole next to you rather than ahead on the other side of the road. Which means you have to watch the indicator, and not the road or traffic. Seems stunningly stupid. I presume an idea from people who have never crossed a road.

They're cheaper to fit, and useful for people with some kinds of visual impairment (and presumably un-useful for others).

[Kim]

What the hell is a blind person supposed to do with it?

Blind people use the cone.  It's less ambiguous than beeps, and doesn't require hearing.

Doesn't help it being in a stupid position, of course.

[trekker12]

Fair enough, just seemed a bit odd to me.

A lot will be to do with local traffic and presumably pedestrian data. I seem to wait far longer at crossings at home in Ipswich where presumably a far greater proportion of people are too lazy to walk (er I mean use their cars) than in London where I hardly ever seem to wait to cross, presumably because in London there is a much greater volume of pedestrians.

[hubner]

And what, for that matter, is with the crossings that mount the crossing indicator on the pole next to you rather than ahead on the other side of the road. Which means you have to watch the indicator, and not the road or traffic. Seems stunningly stupid. I presume an idea from people who have never crossed a road.

They're cheaper to fit, and useful for people with some kinds of visual impairment (and presumably un-useful for others).

I would think cost is the main reason, although "encourages pedestrians to look at the approaching traffic." is given as a reason:
https://www.bedford.gov.uk/transport_and_streets/road_safety/pedestrian_crossings.aspx

Puffin Crossings

A puffin crossing is similar to a pelican crossing, but it has the 'red/green man' signals on the near side rather than the other side of the road. This encourages pedestrians to look at the approaching traffic.

It uses infra-red detection to identify when a person is waiting and also to extend the green man period for people who cannot cross as quickly as others.

If someone presses the button and then walks away, the system detects this and reverts priority to traffic so as not to cause undue delays. 
 
How to use a Puffin Crossing

    At the crossing , stop at the kerb
    Press the button and wait for the 'green man' signal to light up. The infra-red detection will pick you up and by pressing the button will register a demand.
    Do not start to cross if the Red Man is showing
    When the 'Green Man' shows and you are sure that the traffic is stopping, go straight across, looking and listening. If the crossing is staggered treat each half as a separate crossing.
    The signals will stay red for drivers
    Until you get safely across, keep looking all around and listening in case a driver doesn't stop 

[Cudzoziemiec]

And what, for that matter, is with the crossings that mount the crossing indicator on the pole next to you rather than ahead on the other side of the road. Which means you have to watch the indicator, and not the road or traffic. Seems stunningly stupid. I presume an idea from people who have never crossed a road.

Those are the Puffin crossings mentioned by Kim. The logic of putting the light on the box is that the man can go red after a certain time, so people arriving at the kerb won't start to cross, while the red light for traffic can be simultaneously extended in order to allow slower pedestrians (which I expect is most people nowadays) to finish crossing. I think the far-side lights with timers favoured by London and various other places achieve something similar by just blanking out both red and green men, but this is thought by DfT to be disconcerting to the slow-crossers and ambiguous to the arrivers.

IMO, the Puffin light boxes are often situated so that you can't see them at all until you're at the kerb, and then they actually obscure your view of the traffic. For blind people, they have a little twiddly knob underneath.

[Cudzoziemiec]

And what, for that matter, is with the crossings that mount the crossing indicator on the pole next to you rather than ahead on the other side of the road. Which means you have to watch the indicator, and not the road or traffic. Seems stunningly stupid. I presume an idea from people who have never crossed a road.

They're cheaper to fit, and useful for people with some kinds of visual impairment (and presumably un-useful for others).

I would think cost is the main reason, although "encourages pedestrians to look at the approaching traffic." is given as a reason:
https://www.bedford.gov.uk/transport_and_streets/road_safety/pedestrian_crossings.aspx

Puffin Crossings

A puffin crossing is similar to a pelican crossing, but it has the 'red/green man' signals on the near side rather than the other side of the road. This encourages pedestrians to look at the approaching traffic.

It uses infra-red detection to identify when a person is waiting and also to extend the green man period for people who cannot cross as quickly as others.

If someone presses the button and then walks away, the system detects this and reverts priority to traffic so as not to cause undue delays. 
 
How to use a Puffin Crossing

    At the crossing , stop at the kerb
    Press the button and wait for the 'green man' signal to light up. The infra-red detection will pick you up and by pressing the button will register a demand.
    Do not start to cross if the Red Man is showing
    When the 'Green Man' shows and you are sure that the traffic is stopping, go straight across, looking and listening. If the crossing is staggered treat each half as a separate crossing.
    The signals will stay red for drivers
    Until you get safely across, keep looking all around and listening in case a driver doesn't stop 

Wow. I find exactly the opposite; with a little light situated next to your elbow, you're looking down at that and can't observe it and the traffic at the same time. With a light in front at somewhat above head height, and being a much bigger light too, it's quite easy to keep an eye on both at once.

[jiberjaber]

To the OP, looks like that's a trunk road junction, if you want to air your concerns, suggest using HAIL, via http://www.highways.gov.uk/about-us/contact-us/?hc_location=ufi
You should get a holding response back and eventually a response addressing your query - that might or might not answer your questions!

Given it's a motorway/trunk road junction, I would suspect priority (rightly) is for ensuring clear passage of traffic on and off the motorway network and it will aim provide a safe crossing whilst managing the traffic, but its priority will be the traffic.  At a slot in time, the green man will invite the pedestrian to cross if they view it safe to do so and a calculated time for them to cross will be used, on streetview you can see the on-crossing detectors (little black boxes on the poles pointing at the crossing area), these will be used to sense that the ped is still crossing and extend that time if required.

In some places peds are given more priority than vehicles, there are some signals in our city which are actually ped crossing all the time and the vehicles have to wait to be serviced. Its a balance between all road users and also the specific needs of the time of day (priority to main routes out of town between 16:00 - 18:00 for example)

The reason why the ped crossing phase isnt instant is that the traffic signal controller is running through a cycle, which might be controlled through a number of different ways with the various set of lights being called by demand (count of cars say) or a timetable.  When you press the button, it's a bit like putting your hand up in class, the teacher will get round to you eventually, but if there is some higher priority to deal with you'll have to wait for a slot.  Sometimes there is a ped waiting detector to help ensure that if the ped has crossed before the green invitation to cross that teh demand for the pedestrian phase is skipped.

In terms of cycles and triggering lights.  There are a number of detectors that can be used, the worst for cycles is probably magnetometers (detecting the impact on the earths magnetic field by a vehicle) the most common are inductive loops in the road.  You can help yourself be detected by 'shorting the loop', i.e. placing your bike in a position that has the greatest effect on the inductive properties of the loop.  In plain english, ride along the black slot in the road that is the end of the loops, i.e. the bits parallel to the kerb... note some loops do different things (detect queue, clear queue etc) so if in doubt, hit them all up to the stop line!

The above is all very generic but hopefully answers some of the questions and myth in the thread. Plenty more info on the web but without knowing a significant amount of detail about specific sites i.e. the location, control strategy and the reasons behind it, you will always be guessing why it does what it does - signals in Essex for example work differently to signals in London, which all work differently to say signals that are on motorway interfaces... then sometimes they all work the same - you can't fully tell just by what is visible and remember your interpretation of timings etc is just valid for the snapshot you witness it - without knowing the configuration of the actual site, you don't know if it was under remote control, local control, demand driven or timetabled.... or worse still - the detectors are faulty and therefore the expected behaviour is not what is been seen.... the only persons who probably stand a chance in being able to decipher all that would be a Traffic Signal Engineer, which I am happily not one LOL!

[hubner]

Those are the Puffin crossings mentioned by Kim. The logic of putting the light on the box is that the man can go red after a certain time, so people arriving at the kerb won't start to cross, while the red light for traffic can be simultaneously extended in order to allow slower pedestrians (which I expect is most people nowadays) to finish crossing.

I can see the advantage of that, but does that mean as you're crossing, there's no red, amber or green for you to see?

Isn't that's what the flashing amber light is for?

[Kim]

Those are the Puffin crossings mentioned by Kim. The logic of putting the light on the box is that the man can go red after a certain time, so people arriving at the kerb won't start to cross, while the red light for traffic can be simultaneously extended in order to allow slower pedestrians (which I expect is most people nowadays) to finish crossing.

I can see the advantage of that, but does that mean as you're crossing, there's no red, amber or green for you to see?

Indeed, but that doesn't matter, because once you're on the crossing you have priority anyway, and the system should detect you and hold the lights on red for road users until you've crossed.

[Cudzoziemiec]

Flashing amber is only found on a few older crossings now (Pelicans). I think there's meant to be a schedule to replace the remaining ones eventually. Instead, the traffic is held on red till (supposedly at least) all pedestrians have cleared the crossing, then it gets red and amber followed by green in the normal way. In other words, the sequence is the same whether the lights are for a junction or a crossing.

[ian]

We seem to invest a lot of time and effort in ensuring pedestrians know they're second class.

I don't get the puffin thing. It's distracting my attention from the big things that might kill me. It's close to my face and I'm focused on that. I think most people will look aways and attempt to make their own crossing.

I genuinely think that the people charged with thinking up these things have never actually encountered any of their creative solutions.

[Jaded]

They probably drive  everywhere...


I was touring the town with some highways engineers a couple of years ago. They couldn't see any problems. That's because the traffic was all well behaved - the HEs were at work, and therefore in HiVis.

[ian]

That's the problem really. None of these things are visible if you're driving because you have the gift of perpetual priority. Watch the tides part like the Red Sea for Moses as you cruise on through. Same for all those other urban obstructions, not to mention the litter and dog mess on pavements, etc.

[citoyen]

We seem to invest a lot of time and effort in ensuring pedestrians know they're second class.

A recent discussion elsewhere on speed limits got a bit lively when someone suggested this problem could be solved if all 'road users' were viewed the equally in the eyes of the law - so speed limits would apply to both cyclists and pedestrians, but both groups would be in a better position to assert their rights to be on the road.

The fundamental problem I have with this idea is that in law, pedestrians already have more rights than motorists, so it would actually be a reduction of their rights.

And as you rightly point out, highways planners do their best to ignore the rights of pedestrians in the way they design roads and crossings, so merely having rights is worth a fat lot of nothing anyway - as mentioned earlier, I do try to assert my rights at pedestrian crossings, by crossing when the lights are in my favour and have often had to step out of the way of a motorist who refuses to stop.

It's hard to assert your rights against a bully in a high-velocity two-tonne steel box on wheels.

I genuinely think that the people charged with thinking up these things have never actually encountered any of their creative solutions.

I suspect they know that what they're doing is shite but have to stick to the brief given to them by vote-chasing local councils.

It's an utter fucking disgrace. Probably about time someone started a pedestrian equivalent of critical mass.

[jsabine]

It's an utter fucking disgrace. Probably about time someone started a pedestrian equivalent of critical mass.

This gent do you?

(The Mail report is probably better written, mind.)

[citoyen]

This gent do you?

I like the cut of his jib.

[arabella]

See also this thread.
wherein it appears that there is a mandatory wait for pedstrians etc.
Maybe we should just walk down the middle of the road, seeing as we don't need a licance to do so.  As I do on the road I live on.  So far OK, apart from a death threat when I didn't jump out of the way quickly enough.  There was a child in the back of said car ...
Don't get me started on pedestrian crossings that take you mumble yards away from the pedstrian desire line so as not to inclonvenience the motons.