Does pressing the pedestrian crossing button actually do anything? | Hacker News Reader

Does pressing the pedestrian crossing button actually do anything?

bbc.co.uk

59 pointsandyjohnson066 comments

I think there's a good reason to have buttons that do nothing: it improves usability. Imagine teaching a child how to cross the road. The instructions are:

1) press the button

2) wait for green man

3) cross

Now imagine we took away the buttons that do nothing. Now you need two cases, or branching: look for button; if button is present, press it; otherwise just wait - then cross. Obviously this is still trivial but raises the bar a little and introduces greater possibility for confusion. Especially when talking about children, this makes roads easier and safer to cross, which in turn saves lives.

That's definitely an interesting take, and it triggered a thought I had a long time ago.

One thing I've noticed since moving to North America is that children get off the school bus and will essentially just run across the street, including straight in front of the bus, because they know the traffic around them has stopped.

I can only imagine that that leads to some sort of subconscious thinking that can only be dangerous once they are not on a school bus...

It is. Two summers ago, a kid from my school got off a city bus, walked in front of the bus and into the street and was hit by a car and killed.

Having the buttons everywhere also provides for future flexibility.

Just because a button is ignored now, doesn't mean that it will always be. Special events, changing traffic patterns, or changes to traffic flow optimization strategies may some day necessitate the use of the button.

If the button wasn't already there, it would have to be installed, which takes time, money, and planning.

Plus less mental burden for everyone. You get to a light, you press the button. No need to wonder if there is going to be a button or not, no need to have to look all around - in case the button was hiding somewhere else.. The button is there..press it.

Often in Australia, pressing the button makes the pedestrian light go green. But it has no effect on signal order (it goes green when cars traveling in the same direction get a green light).

What's the point of making us press a button in this case? Why not give pedestrians a green light automatically?

Even more obnoxious are intersections where the pedestrian light times out from green to red, but cars still have a green light. You can press the pedestrian crossing button and get a second walk cycle.

Again, why not just make the first walk sequence longer?

It seems traffic planners don't care about pedestrians.

It seems traffic planners don't care about pedestrians.

You got that right. I walk 4+ miles/day on city streets and I've noticed a steady erosion of rules designed to make pedestrian life safer and easier. What you mentioned above and this:

In addition to lights which are timed to not give a "go" signal to pedestrians unless they push the button, I've run across one that will make you wait until the next cycle unless you press it before the current cycle begins. That is, I push it a second after I would have gotten the "go" signal and I have to wait an entire cycle before it actually tells me to walk. The effect of this? I go anyway, but because the cycle without pedestrians is shorted this is quite dangerous.

Here's another trending in my city: buildings which sit directly on streets with parking lots that empty onto streets having their own lights, have separate lights for pedestrians to regulate them while on the sidewalk. So, you're walking down the sidewalk, no where near an intersection and a car comes out of a "driveway" at 20+ miles/hour. Freaked me out the first time this happened. I could have easily been killed as the car was just a few feet from me.

My guess: some city planner was paid off to allow this completely unsafe situation.

At least you have sidewalks!

It amazes me how many communities (here in the USA, at least) just completely omit them altogether. They're so car-oriented that they actually deny the possibility of walking altogether. You get the feeling that they'd ban shoes if they could. Depressing.

> trending in my city: buildings which sit directly on streets with parking lots that empty onto streets having their own lights, have separate lights for pedestrians to regulate them while on the sidewalk

The Hilton in downtown Philadelphia has one of these. Fortunately there's also an audio cue. Unfortunately, you're on a ten foot wide sidewalk and certainly aren't expecting the beeper to be about you. It's a recipie for squashed pedestrian.

When I was young, on my route to school there was a bicycle crossing that worked like this. Cars always have green unless there's a car approaching from the side street. Bikes always have red unless they press the button. So when I approach at reasonable speed and see that the cars have green, I have to stop, press the button, and then build up all that speed again.

Nobody does that. Until there was a police car hidden just after that crossing. I suspect it was a very good day for fines.

In York (UK) it is a mixed bag. There are a couple of simple pedestrian crossings near my home where the lights never change without a press and change very quickly once requested. At junctions it is more complex and seems to vary: some definitely have their sequence altered by specific pedestrian requests, some definitely seem not to. I've not noted if any vary by time of day, as some people report.

Well this is a rare treat, a fellow York dweller, greetings!

What? 3 of us? Heavens!

4 actually!

We might need a few more than that before practical world domination plans can be conceived...

Any crossing near a school will generally change very quickly after a button press, but only during the school-run hours. Knowing which these are can noticeably accelerate ones journey to and from work.

There's a light near my apartment that takes about 4 full minutes to change (it's a small-road-onto-big-road intersection), at all hours of the day. However, the walk light changes the light instantly.

I leave for work around 6 each morning, when there's nearly no one else on the roads. Since it's so frustrating to watch an empty road for four minutes, I have actually gotten out of my car, hit the button, and gotten back into my car to accelerate the light change.

Probably easier to just treat it like a stop sign rather than actually getting out of your car if there's no other traffic.

There's some next-level traffic light voodoo I often see people attempting in the UK, which is repeatedly pressing the button. I like the idea that it's a democratic process: only when pedestrians outnumber cars will the lights change.

People go a bit further in Australia. I've heard many different peoples stories of timing (you push it and hold for 7 seconds) or repetition (12 presses and it'll change right now). Complete nonsense of course, but it's amusing how far positive reenforcement can get a story.

This reminds me of Skinner's superstitious pigeons:

http://en.wikipedia.org/wiki/B._F._Skinner#Superstitious_Pig...

That was a very good read, thanks!

I've seen people do this with the Clear button on calculators. They press it repeatedly, presumably in the belief that extra presses make it "really cancel". Something to do with their mental model of the calculator's internal state?

I used to do this. It's because of the confusing presence of the AC button. The UI has made clear to you that there are multiple levels of cancellation, one can in fact "really cancel." We know full well that there is some overcomplex internal state to the device, and rather than reading the manual for a calculator (honestly) we hammer the cancel button a few times, just to make sure.

I hadn't thought of that, but it makes sense.

A quick search reveals that some calculators have an AC button (clear everything) and a C button (clear last entry), while others have C (clear everything) and CE (clear last entry). Definitely confusing.

I'd forgotten about CE. Even worse.

Some calculators do function this way. Pressing the clear button once clears the current screen but doesn't clear the equation. Pressing twice clears everything.

Pressing the button repeatedly until the light changes distracts them from the wait time so it feels faster. Effectively it works, technically it doesn't.

I pay way too much attention to these things. I have found on my walk to work, some buttons which do nothing, some which you must press and some you must press if it is after 10pm.

At least where I live, it depends on the intersection. So don't assume anything.

"The short answer is - it depends. At a standalone pedestrian crossing, unconnected to a junction, the button will turn a traffic light red

At a junction it is more complicated."

That's all you need to know.

I've been to places where the 1st case applies. Press the button, the car signal turns yellow immediately (light traffic and light pedestrian traffic)

At a crossing, let's see, you got there and you pressed the button, then another person came and pressed the button to cross the other street (meaning, traffic where you want to cross)

No system can make sense of these requests, and the traffic has to flow. Makes sense to just go through the movements and ignore the buttons.

>No system can make sense of these requests, and the traffic has to flow. Makes sense to just go through the movements and ignore the buttons. //

One may not be able to mathematically ensure optimal operation but you can certainly "make sense" of the requests.

Surely you read the inputs and only include the pedestrian crossings in the lighting sequence if the buttons are activated. Unless you're halting the traffic for some ulterior flow management need.

As for non-interrupt raising buttons - the "WAIT" light should show to indicate the button isn't required to be pressed.

Lastly, some crossings in the UK have what appear to be cameras (I assumed some form of wide angle IR sensor) facing the pedestrians. I assumed these could provide input as to density of pedestrians waiting in order to balance flow of pedestrians vs. road traffic. Anyone know certainly what they're for?

Responding to the last part of your comment the sensors are there to cancel the crossing request if the pedestrian crosses early or wanders off elsewhere, to avoid stopping traffic for no reason. The sensors pointed at oncoming traffic can be used to halt traffic if they detect it's moving too quickly for the area. Crossings with the sensors and the don't walk/walk lights on the side closest to you are puffin crossings. The other ones are the older pelican crossings. Infos from http://en.wikipedia.org/wiki/Puffin_crossing

"and only include the pedestrian crossings in the lighting sequence if the buttons are activated"

That works for a pedestrian crossing, but not where we have two lanes of cars crossing.

Or if you think in more complicated crossings like O'Connell Bridge in Dublin, there's probably no way the buttons could have any input in the lights there without messing the traffic.

Not sure what the cameras you mentioned do, maybe it's the usual "Big Brother" cameras

Some crossings here, UK, have turn filters; some have full pedestrian access (ie diagonal crossing of a crossroads is enabled). Whilst it's possible to have a sequence in which some roads necessarily have halted traffic usually on single carriageway roads [one lane per direction] it's still an optimisation to ignore the pedestrian phase of the sequence.

Yes actually, here in Sweden you have a lot of buttons with a light under it. I just love seeing people who don't understand these crosswalks, when the light is on, that's when your timer is actually counting. When the light is off, there is no timer counting down to let you cross.

So some people get to the light, and wait, thinking it's one of the many automatic crosswalks. But it's not! The light must be pushed! So they just stand there forever until they finally think "screw law, I'm crossing".

That is funny to me. :)

The linked "secret button" article discussion is at https://news.ycombinator.com/item?id=5792039

A piece of (old) satire on the pedestrian button hacks: http://www.bbspot.com/news/2005/06/crosswalk_button_hacks.ht...

The most fascinating part of this for me is that people _actually_ pay attention to the green and red men at crossings, and even to crossings at all. I mean, sure, where I live children or older people who can't walk very fast wait for the green man but most regular folks just go and cross where and when they please.

I believe in Paris all of these are entirely automatic ; though there are buttons that are here to help the visually impaired by telling them where they are and if they can cross safely.

Washington, DC, has many signals that have a countdown. Usually I figure on 3 seconds per lane at a moderate walking pace. Other times I will use my knowledge of how long the don't walk signal lasts before the crossing traffic gets the green light; if I don't know the intersection well, I won't cross on a don't walk.

All this of course assumes that there is traffic on the street I want to cross, which is true for most times of day, most places I walk.

Crossing against or without lights seems to depend very much on culture. In some parts of the US it is unremarkable, in others it is looked down on.

This is fine on quiet roads, but doesn't work in busy cities. If you tried to cross the road on my walk to and from work without waiting for the traffic to be stopped you'd get hit very quickly!

edit: perhaps you live in Paris? In which case I don't envy you having to cross the roads there!

> This is fine on quiet roads, but doesn't work in busy cities.

I guess I can claim to have lived in Shanghai for a span of (not many) years, and I have to dispute this. People will just walk out into the middle of a busy street, making lane-by-lane progress much like Frogger if they have to. They do it because the only real alternative is not crossing the street at all. When I was working at an international school here, it was common (and, in my view, completely justified) for new arrivals to want help crossing the street. But the fatality rate is quite low. ;)

I do. I think it's a cultural thing, people around here tend to not respect the rules very much, myself included.

I must admit this behavior is less frequent in the busiest streets in town but even there it's no rare sight.

In France jaywalking doesn't exist in law, and cars are always required to give way to pedestrians crossing or looking to cross. The only thing to be aware of is, if you cross less than 50 meters away from a crossing, and there is an accident, the driver's insurance may not be liable.

In my hometown they replaced old buttons that emitted a sound and a visual cue (green light silhouette on the device) with touch-sensitive devices that doesn't blink, sound or anything. For months we kept on 'pushing' on it and then once or twice I saw some of them being lit for a few days and now they still seem to be 'dead'. Something's wrong with the interface and the local authorities badly managing urban infrastructure.

Over the past few years in my neighborhood in Los Angeles they have been replacing the older yellow buttons (that people tend to hit 10 million times thinking it will make the light change faster) with newer ones, which are really great. When the button is pressed, makes a loud click, a red light comes on, and it stays depressed until the signal changes. They've also added in that rat-a-tat-tat clicking that I assume is for blind people. Some people still pounce the button but I've noticed most tap it a single time. I'm a big fan and I'm sure the city is too as it probably cuts down on wear and tear.

In terms of actual crossing, it is worth hitting the button at some lights, so that they know there are pedestrians (otherwise it could be a green light and you still have a red hand) and other times there's always a way for a pedestrian to cross, usually with a countdown timer after a certain amount of seconds. Every ped crossing in LA seems to have a countdown timer, which is great, for peds and even drivers (it gives you an idea when the light is about to change).

And remember, this is Los Angeles, not really a city known for pedestrians so I think the city has done a good job for the most part.

Pretty sure it alerts the system that there are pedestrians waiting to cross, otherwise why stop traffic if no-one is there?

So, do you think the quotes from people running the system who say that is not the case are lying for some reason? Or do you think you know more about how their system works than they do?

The question still stands. Why interrupt the road traffic if there are no pedestrians waiting? It's possible to answer that "for flow control" but I'd warrant that's not an effective proposition for the majority of junctions.

I didn't see this specific question addressed in the OP so it's quite possible it was simply glossed over to provide a simplified answer or the reporter worked around it to make it easier to express the sequence.

For me the most interesting piece in that article was the image of a crossing where pedestrians can actually walk _across_ the crossing (like, diagonally) instead of just a single street.

Haven't seen those anywhere here and I assume those are actually kind of nasty for car traffic (since .. all directions need to stop). Fascinating :)

They are called scrambles, there are a few in the UK but they are much more common in Japan. As you surmised they only really make sense when there are a large number of pedestrians and vehicular traffic has a low priority.

When I took traffic engineering at university we were taught that crossing layouts like this where pedestrians can move more freely are statistically much safer as drivers drive much more carefully. Another example is Exhibition Road, where the entire road is shared between pedestrians and cars.

http://en.wikipedia.org/wiki/Exhibition_Road

Many intersections (like California/Alaska Junction in West Seattle) have all-way pedestrian crosses, which are safer when you think about it (can walk diagonal, no worries about right turns).

Edinburgh uses them quite a bit. The problem is that these mean a different way of traffic flow. Usually, you do asynchronous switching, meaning all in one direction, then all in the other etc. Here however, you have to switch differently. All directions pedestrians → Car direction 1 → Car direction 2 (or have loads of cars that want to turn block each other in the middle of a junction.)

That picture is of Oxford Circus, one of the busiest intersections in the UK. There are very few crossings similar to that one here.

http://en.wikipedia.org/wiki/Oxford_Circus

Obligatory Shibuya video: http://www.youtube.com/watch?v=mVXuN28Ismk

I'm fairly convinced, with the exception of a handful, pretty much all the crossing buttons in Brooklyn NY are placebos.

I've seen people roundhouse kick the thing (not an exaggeration) and it makes sense to have one that doesn't work since if it did previously, this treatment would kill it in no time.

Also, newer ones are popping up that aren't spring based, but are touch sensitive instead. Basically a shiny Aluminum or Zinc knob that beeps to let you know it's pushed. I think these are more effective since with the old ones, you're not even sure if the push got received.

It makes sense to have buttons that work in places where people actually expect functionality and such is desired. Not in a place where the default is impatience followed by vandalism.

> Also, newer ones are popping up that aren't spring based, but are touch sensitive instead

This is the standard type in Sweden. http://imgb.mp/jie.jpg The whole front plate is touch-sensitive, it beeps and the light on the bottom lights up after it's been pressed until you can cross the street. I've never seen one not working, so they must be pretty vandalism-proof.

in the usa, i've definitely seen lights where a larger road crossed a smaller one, and the small road green light stayed green longer if someone had pressed the pedestrian crossing button. which does seem like a sensible use of the button - from a flow-control point of view you want the large road green a lot more of the time than you want the small one green, but if someone is walking across they're going to be potentially a lot slower than the traffic (people with walkers, e.g.)

Not nearly as annoying as lift/elevator buttons.

We have our lift buttons on the outside. You choose your floor, and are directed to one of the 6 lifts available. This seems to confuse every visitor to the building, who will walk into the first open lift (that will have opened for someone else). They spend 5 seconds looking for the buttons, the door closes, and they're stuck going to a floor they never wanted.

However, as the buttons are on the outside, the designers clearly thought they would aid things where a large group all want to go to the same floor. Press the special people button, enter how many of you there are, and the lift system will optimise to ensure it doesn't needlessly stop at interim floors if you have filled that lift to capacity, or send you a lift already filled that wouldn't fit your group in.

So the trick is to say, even if you are a single rider (lifter?), that you are a party of 14, guaranteeing your lift won't stop at any other floor on the way to yours. An 'express mode', if you will.

Problem is, everyone working in the building seems to know this trick, and it does not scale. Whilst it might make the time in the lift shorter, I notice that the wait time for a lift appears longer (from observing those going to my floor who have done the trick before I then select the same floor normally). The real trick then is to use the lifts as they were intended. The irony is that all these 'super busy' types who are slowing everyone up are simply slowing themselves up too.

Then again, who was expecting a building full of lawyers and traders to behave like good citizens?

There is a persistent myth that some elevators (aka 'lifts' in my part fo the world) have an express mode that can take you to a chosen floor by pressing the door close button in conjunction with the appropriate floor button [1]. As far as I know its false. I try to avoid using elevators, but the ones I do use always seem to have a key slot to allow them to be put into 'privileged' mode.

[1] http://www.newyorker.com/archive/2005/10/17/051017ta_talk_pa...

See my other reply for the perils of an express mode, which the lifts in my building do have (of a sort), and everyone knows about.

https://news.ycombinator.com/item?id=6326890

You need a paternoster lift:

http://www.youtube.com/watch?v=tAjYAfb_HPk

One of the buildings at the university I went to had a Paternoster. Great fun, and rather more rapid that conventional lifts because there is no door open/close cycle to wait through.

The main disadvantage was that it was fairly easy to trip the sensor that detected when a body part was jammed in the opening to the lift compartment. When this happened, the compartments would come so a sudden stop - potentially between floors - until the janitor could be roused from wherever he was sleeping to restart the mechanism.

An anxiety-inducing urban myth foisted on new students was that the compartments inverted as they passed the top or bottom floors. This could be re-enforced by staying in the compartment at these points and doing a handstand as it came back into view. Seen it done.

If a traffic light is dumb (and most are) and the government wants to optimize traffic flow, then a button that disrupts the timing will mess up the traffic flow. An intelligent light controller might be able to include the random changes and still optimize the flow. Sadly very few light controllers are smart enough to do this.

I like the UK system and the way its implemented.I doesn't have to respond to a button push all the time plus you can always cross if you believe it's safe to do so.

Makes a lot more sense them forcing people to stand at a red light uselessly.

There's also sound for the blind integrated with the buttons in Germany. Removing a placebo button would also mean removing that extra sound. You could probably separate the two functions though.

In Amsterdam, it activates the clicking sound for blind people. Very convenient if you're blind, I presume (I've never been blind for long enough to give it a try).

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