Author Topic: Merged thread: Countdown graphics, Nearside pedestrian figures, etc etc  (Read 29385 times)

EDIT someone merged my threads.

I have discovered some TfL pdfs documenting the development of the amber pedestrian crossing countdown units  (used on 'dumb' fixed time crossings)  in London:

it seems the Dft rejected the suggestion of a graphical indication of time remaining in favour of literal  digital seconds:

this seems slightly weird to me (in a UI sense):

surely showing seconds left suggests arriving Pedestrians doing maths to decide between the 3 or 4 notional ideas I expect them to hold when deciding if there is still time for them to cross in time:
1) near start of blackout countdown = plenty of time to cross at a reasonable walking speed
2)  enough time for slightly faster speed walkers to start crossing(I suppose this state could be subdivided into two)
3) Best not to start crossing unless you are flash the superhero :) but time to finish crossing

(I expect very slow persons would only start on the green man)
So that could be a discrete / quantised 3 bar display eg  = =_
or some sort of more analogue indication  etc etc

Does anyone know their reasoning?

NB discussion of whether countdown as implemented is a good or bad idea belongs in another thread :) (although I do think some sort of positive indication of longer 'blackout period's is a good thing as it avoids signals looking broken (NB they rejected a (flashing) amber figure))

Basil

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Re: Pedestrian amber countdown displays: why was numeric chosen over graphic
« Reply #1 on: 02 November, 2016, 01:10:35 pm »
Yes, saw one of those near Paddington station the other day.  I only realised what it was after crossing.
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Kim

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Re: Pedestrian amber countdown displays: why was numeric chosen over graphic
« Reply #2 on: 02 November, 2016, 01:11:27 pm »
I expect the actual reasoning was something like "The numeric displays were cheaper".

Though thinking about it, I'm not sure it's bad UI.  Seconds mean something.  You know (or can work out for future reference) how many seconds it takes you to cross a road.  It's the opposite of those TFL cycling distance signs which use minutes, rather than a measure of distance:  Good propaganda, poor UI.

An 'is less than' comparison is barely arithmetic.  I suspect the typical human, when comparing, say, '6' to '11' will use a "does it come later in counting order" algorithm, perhaps applying a "how many digits" heuristic, rather than doing true arithmetic.

A proportional indication (count the bars sort of thing) would look pretty, but just be harder to compare with your time it takes to cross safely threshold.  What does a bar represent?  Are they ticking down at the same rate?  Can you tell how many bars there actually are without squinting?  The possible exception would be studio clock style ring of dots, with 6° representing a second, which some people might prefer over digits, although it ostensibly does the same thing.

If I were designing it, I'd put a studio clock ring around a digital countdown.  Best of both worlds.

Kim

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Re: Pedestrian amber countdown displays: why was numeric chosen over graphic
« Reply #3 on: 02 November, 2016, 01:20:32 pm »
That said, I was interested to see the Dutch approach to this, which I hadn't come across before:  An electromechanical clicker in the push-to-cross button unit, which varies its click frequency according to the state of the lights (about 1Hz when red, 2Hz when green, speeding up in the few seconds before it changes back to red).  This fulfils the same purpose as both the beeper and tactile rotating knob on British crossings, as you can feel the vibration by touching the unit, while being both easier to locate by hearing (as it's not a pure tone sound) and less irritatingly loud than a typical pelican crossing.

Cudzoziemiec

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Re: Pedestrian amber countdown displays: why was numeric chosen over graphic
« Reply #4 on: 02 November, 2016, 01:22:51 pm »
What is pedestrian amber?
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Cudzoziemiec

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Re: Pedestrian amber countdown displays: why was numeric chosen over graphic
« Reply #5 on: 02 November, 2016, 01:24:58 pm »
That said, I was interested to see the Dutch approach to this, which I hadn't come across before:  An electromechanical clicker in the push-to-cross button unit, which varies its click frequency according to the state of the lights (about 1Hz when red, 2Hz when green, speeding up in the few seconds before it changes back to red).  This fulfils the same purpose as both the beeper and tactile rotating knob on British crossings, as you can feel the vibration by touching the unit, while being both easier to locate by hearing (as it's not a pure tone sound) and less irritatingly loud than a typical pelican crossing.
I remember something similar in Stockholm about 1989, except those ones were irritatingly loud. They were also potentially confusing as several close together would all click, so you'd need some other way of knowing which one was clicking at which rate.
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Re: Pedestrian amber countdown displays: why was numeric chosen over graphic
« Reply #6 on: 02 November, 2016, 01:37:33 pm »
I see these regularly at the north end of Waterloo bridge. The count down starts at 15s and is followed by a short all red, but is really useful to the north bound cyclist who can see the ped countdown from the ASL and then prepare to race the busses through the Aldwich. Mind I am normally there on a Sunday morning when the traffic levels are substantially lower.

Kim

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Re: Pedestrian amber countdown displays: why was numeric chosen over graphic
« Reply #7 on: 02 November, 2016, 01:42:20 pm »
That said, I was interested to see the Dutch approach to this, which I hadn't come across before:  An electromechanical clicker in the push-to-cross button unit, which varies its click frequency according to the state of the lights (about 1Hz when red, 2Hz when green, speeding up in the few seconds before it changes back to red).  This fulfils the same purpose as both the beeper and tactile rotating knob on British crossings, as you can feel the vibration by touching the unit, while being both easier to locate by hearing (as it's not a pure tone sound) and less irritatingly loud than a typical pelican crossing.

I remember something similar in Stockholm about 1989, except those ones were irritatingly loud. They were also potentially confusing as several close together would all click, so you'd need some other way of knowing which one was clicking at which rate.

Well, it can be quite irritating if there isn't much traffic noise, but the sound doesn't seem to carry very far (certainly compared to the BEEPBEEPBEEP of a British pelican).  I like the way that it provides continuous auditory indication that there's a crossing there for the visually impaired.  With multiple clickers in close proximity it can become a bit of a cacophony, but you can discriminate which is which by stereo hearing (if you have it) or touch.

We solve that problem by not using any beepers where there are multiple crossings close together, so solo visually impaired users have to find and use the knob.

I wonder what the service life of the clickers is like?  Of course, the Dutch attitude to road maintenance probably extends to traffic lights, rather than the British system of only replacing them when somebody drives into them, unless the whole thing needs digging up for some reason.

caerau

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Re: Pedestrian amber countdown displays: why was numeric chosen over graphic
« Reply #8 on: 02 November, 2016, 02:06:14 pm »
These have been going in the USA since forever as far as I know.


I saw one in Philadelphia once and I did vaguely wonder what I'd think if I was 80 years old with a stick and the THREE  - TWO - ONE... started when I was halfway across.  It didn't appear that the traffic would do anything but mow them down...
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Re: Pedestrian amber countdown displays: why was numeric chosen over graphic
« Reply #9 on: 02 November, 2016, 02:11:52 pm »

Though thinking about it, I'm not sure it's bad UI.  Seconds mean something.  You know (or can work out for future reference) how many seconds it takes you to cross a road. 
A proportional indication (count the bars sort of thing) would look pretty, but just be harder to compare with your time it takes to cross safely threshold.  What does a bar represent?  Are they ticking down at the same rate?  Can you tell how many bars there actually are without squinting? 

My OP listed what I thought the bars could mean (and the example I gave had just 3...) ?
I am not sure it matters if they are not exactly equidistant in time but I expect they would be pretty much so (and of course would vary in length between crossings because they don't indicate time itself: more whether its safe to start crossing for various speeds* of walking (those speeds would have to be consistent of course). *Slow/fast/medium.

When crossing I would never think in terms of seconds it takes me to cross: but pelicans are diivided into two periods and, as flashing green figure phase starts, if someone still on crossing (to make cars wait) a brisk (but slightly naughty :) ) walker  could start and complete the crossing within that phase: extending that sort of logic to a 3 or 4 element bar graph etc  seems more intuitive to me that thinking in seconds.
I had thought if I came across a countdown display I would subdivide it into 3 and treat it like my
bar graph ...

The possible exception would be studio clock style ring of dots, with 6° representing a second, which some people might prefer over digits, although it ostensibly does the same thing.

If I were designing it, I'd put a studio clock ring around a digital countdown.  Best of both worlds.
The circle is nice idea but I'd still use the  fully lit circle to indicate max countdown time left(so the dots per second would vary) as the digital seconds provide the exact time info for those pedestrians that want to do seconds based thinking.   Thus catering for quantised numeric thinking pedestrians and fractional thinking pedestrians :).

Dibdib

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Re: Pedestrian amber countdown displays: why was numeric chosen over graphic
« Reply #10 on: 02 November, 2016, 02:52:07 pm »
I'd say that, for me, a seconds-based countdown would be the most intuitive.

And I only think that one would have to do "maths" to work out whether they can cross in time in the same way one has to do "geometry" to catch a ball - a lot more of it is instinctive rather than conscious thought, IME.

Kim

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Re: Pedestrian amber countdown displays: why was numeric chosen over graphic
« Reply #11 on: 02 November, 2016, 02:52:19 pm »
The circle is nice idea but I'd still use the  full circle to indicate max countdown time left(so the dots per second would vary) as the digital seconds provide the exact time info for those pedestrians that want to do seconds based thinking.

I'd deliberately use a 60-second circle, even if it only used a fraction of the range, as that would work intuitively for people used to thinking about time in terms of analogue clock faces.  I never really developed an intuition for analogue clocks, and would prefer a digital display, but I know someone who's very dyscalculic, who always visualises counting around a clock face in order to make sense of quantities of time.  Change the rate, and it's just a misleading version of your bar graph, where they have to start guestimating fractions.


Units aside, I think the main point of these displays is to give a much higher resolution than the usual two phases, in order to precisely match a given pedestrian's crossing speed, so they know when not to cross.  3 or 4 is states is only a slight improvement over two.

Re: Pedestrian amber countdown displays: why was numeric chosen over graphic
« Reply #12 on: 02 November, 2016, 03:35:16 pm »
I'd deliberately use a 60-second circle, even if it only used a fraction of the range, as that would work intuitively for people used to thinking about time in terms of analogue clock faces.]

Hmm, upon further thought I think the proposed intelligent variants that count waiting pedestrians(at red figure)   then  extend the green figure's  'invitation to cross' appropriately then measure walking speed and adjust the following countdown period  appropriately wouldn't work with my full circle = max idea because that would then vary at the same crossing. Bah, you win :)

EDIT I suppose that answers my OP a bit.

EDIT musings on the intelligent variant moved to its  own thread.

Re: Pedestrian amber countdown displays: why was numeric chosen over graphic
« Reply #13 on: 02 November, 2016, 04:07:22 pm »
Numeric countdown has been common at controlled pedestrian crossings all over the US for a long time and seems to work reasonably well. Traffic engineers tend to be cautious about new, untested implementations, so I wouldn't be surprised if they went with the solution that's known to work.

Just like in the UK, US law (generalizing) says you mustn't proceed if there's someone still on the crosswalk, regardless of what the lights say. Doesn't always happen that way in reality, of course.

Jaded

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Re: Pedestrian amber countdown displays: why was numeric chosen over graphic
« Reply #14 on: 02 November, 2016, 05:28:21 pm »
What is pedestrian amber?

There'll be a film based around something in it in 160m years time. "Plastic Park".
It is simpler than it looks.

Kim

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Re: Pedestrian amber countdown displays: why was numeric chosen over graphic
« Reply #15 on: 02 November, 2016, 05:31:02 pm »
'Plastic' as a geological period?  I suppose that makes sense...

Jaded

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Re: Pedestrian amber countdown displays: why was numeric chosen over graphic
« Reply #16 on: 02 November, 2016, 05:47:29 pm »
I think it has been informally mooted on the basis of the amount of plastic that has already been deposited.
It is simpler than it looks.

Cudzoziemiec

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Re: Pedestrian amber countdown displays: why was numeric chosen over graphic
« Reply #17 on: 02 November, 2016, 06:06:12 pm »
What is pedestrian amber?

There'll be a film based around something in it in 160m years time. "Plastic Park".
Walkers trapped in the solidified resin of traffic.
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Cudzoziemiec

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Re: Pedestrian amber countdown displays: why was numeric chosen over graphic
« Reply #18 on: 03 November, 2016, 07:49:05 am »
On a related note, this suggests that some pedestrian crossings change to green on a set cycle even if the button has not pressed. I find this – as opposed to the arrival of the green, once the button has been pressed, being dependent on a gap in the traffic – rather surprising. Can it really be so?
Quote
In 2013 it emerged that many buttons on pedestrian crossings in Britain are fakes, with traffic controlled by an automated system rather than the request of walkers.

Thousands of junctions across the country operate on a Split Cycle Offset Optimisation Technique.

It works by “vehicle detectors” adjusting the lengths of time between the traffic being stopped depending on how heavily the roads are being used at that time.
Nothing new or surprising there. But it goes on to say:
Quote
In Edinburgh between 50 and 60 of 300 junctions have crossings where the green man comes on automatically, while in Manchester 40 per cent of the buttons are placebos and don’t need to be pressed to stop the traffic at busy times.
So the green man phase will come on even if no one's pressed the button. They seem to be referring to junctions rather than specific pedestrian crossings, but even so, in the UK that means all-directions red for vehicles.
http://www.telegraph.co.uk/science/2016/11/02/close-door-buttons-do-work-in-british-liftsbut-not-in-us-elevato/
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Re: Pedestrian amber countdown displays: why was numeric chosen over graphic
« Reply #19 on: 03 November, 2016, 09:07:06 am »
So the green man phase will come on even if no one's pressed the button. They seem to be referring to junctions rather than specific pedestrian crossings, but even so, in the UK that means all-directions red for vehicles.
http://www.telegraph.co.uk/science/2016/11/02/close-door-buttons-do-work-in-british-liftsbut-not-in-us-elevato/

I must confess that when I got to the bit in the article about Split Cycle Offset Optimisation Technique, I had to check the headline to see if it was written on April 1st.   ;)

cygnet

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Re: Pedestrian amber countdown displays: why was numeric chosen over graphic
« Reply #20 on: 03 November, 2016, 10:19:52 am »
I must confess that when I got to the bit in the article about Split Cycle Offset Optimisation Technique, I had to check the headline to see if it was written on April 1st.   ;)

I'd heard of SCOOT, but never seen/read the un-abbreviated version before.
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Cudzoziemiec

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Re: Pedestrian amber countdown displays: why was numeric chosen over graphic
« Reply #21 on: 03 November, 2016, 10:59:32 am »
It should really have been something along the lines of Split Cycle Offset Technique to Eliminate Red, in order to fit in with PELICAN, PUFFIN and so on.
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Re: Pedestrian amber countdown displays: why was numeric chosen over graphic
« Reply #22 on: 03 November, 2016, 11:48:31 am »
I dislike the TfL implementation (of seconds left until green for motor traffic), as I seem incapable of interpreting it as anything other than "3 seconds  - sure, that's plenty of time to get across the road."

I much prefer what I've seen elsewhere (eg between Terminal 1 and the car park at Dublin airport), where it's seconds left until the pedestrian green - I'm much happier with "OK, only 45 seconds to wait, there's no point in trying to dash across."

Cudzoziemiec

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Re: Pedestrian amber countdown displays: why was numeric chosen over graphic
« Reply #23 on: 03 November, 2016, 12:03:25 pm »
I have a feeling that the crossings in Rzeszów, SE Poland, had both; countdown to pedestrian green and then once that starts, countdown to its end – in different colours. But perhaps my mind is conflating different systems seen in odd places into one seen where I was surprised to see any.
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Re: Pedestrian amber countdown displays: why was numeric chosen over graphic
« Reply #24 on: 03 November, 2016, 01:03:50 pm »
I dislike the TfL implementation (of seconds left until 'red figure reappears(which will be followed by a brief all red period))'# , as I seem incapable of interpreting it as anything other than "3 seconds  - sure, that's plenty of time to get across the road." #very slightly corrected by SA_SA_SA_SA

I much prefer what I've seen elsewhere (eg between Terminal 1 and the car park at Dublin airport), where it's seconds left until the pedestrian green -
If the countdown to green is on the nearside wait/request panel presumably both  types could be provided* and those such as yourself who don't wish to do maths (whilst crossing the road) can simply view the farside amber countdown (previously blackout) period as a simple amber lamp: giving positive indication/reassurance(that crossing is still working: a blackedout signal might be confused as broken...)  to  those on the crossing but telling maths hating (whilst crossing the road) persons , like yourself, at the kerb to wait till next green figures 'invitation to cross' or an empty road...

EDIT I wish to clarify that above I only, jokingly, meant maths-hating in relation to calculating whether the displayed amber countdown seconds leaves you enough time to start and finish crossing. Sorry. I have added the bits in italic. :)

*just use white/pink-ish red digits for the nearside countdown to green (red figures on black hard to read for colour blind)?