Would a 'Processing' indicator on pedestrian crossing controls be helpful - and if so how would it be designed?

Question

Pedestrian Crossings used to be simple things where you pressed a button and light went on saying 'wait' and then you waited until the red man turned to a green man.

However, modern crossings in the UK are 'computerised' and react to the inputs from a number of sensors - so that their time to react to pressing the button is variable.

Would it therefore be useful to have some kind of display on the 'wait' panel which gave an indication of 'processing' - such as the ubiquitous spinning disk icon - or would a more complex indicator be required ?

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Edit: Observing people's actual behaviour at crossings shows that people often don't 'obey' the crossing but make their own decisions about when to cross.

I'd argue that this is down to the apparently 'random' behaviour of computerised crossings (sometimes it reacts quickly when you press the button, sometimes it reacts slowly).

And there is no feedback from the crossing display indicating that anything is happening ( on software you'd use a 'loading' indicator )

Answer 1

No, "processing indicators" would not be helpful. Crossings are used by a wide range of people -- the elderly, the young, the partially sighted, the very distracted, etc. The output should only be used to convey two states: (a) it is not safe to cross, and (b) it is safe to cross. The design is simple to accommodate everybody.

By showing a "processing" sign, you are indicating to the user that a change of state has occurred. When a change of state occurs, the human response is to take action first, think later -- this is called automaticity. At a crossing, this would be very dangerous: it only takes the half a second to walk forwards without thinking, and you could be struck by a vehicle.

Countdown timers in the "safe state" to show how long the user has to cross can be useful. The user's response here doesn't put them in danger. But, the "not safe state" should be clear and consistent.

Answer 2

On British pedestrian crossings at least, when pedestrians press the button to request the lights change in their favour, there is a "Processing" signal to acknowledge the request and let them know that something is happening.

On the older Pelican crossings it's the illuminated WAIT on the button panel.

 ^{Image by Secretlondon from Wikipedia}

Because Puffin crossings have the "red man" symbol immediately above the button, they don't have the word WAIT, but a simple red indicator light. While their timing sequence is slightly different, it serves the same purpose: to let pedestrians know that they have caused something to happen and the lights will change in due course.

There's no need for anything more complicated.

The use of the word WAIT in one case and the red indicator light in the other is supposed to stop an automatic reaction that that change of state means "Go".

Answer 3

Yes, make the button light up.

You see this used in elevators or lifts to indicate the button is pressed and something is happening. It is helpful to indicate to the user the button is operational and does not need to be pressed again. In the cases where this does not occur, it's common to see users pressing a button multiple times and looking around for some indication that an elevator is coming.

I would argue pedestrian crossings would benefit from the same feedback. Pedestrians would know the system received their command and they should wait for the system to indicate the street is safe to cross - as opposed to wondering if the button was pressed and trying to press it again.

Answer 4

Giving information to users, in this case pedestrians, is always a good thing. Especially if it can be done in a way that it doesn't clutter the view of the task the pedestrians are going to accomplish.

A count down sign across the street would be a great way to inform pedestrians on how long they have to wait (and for how long they can continue interacting with their smartphone until they can walk across the street).

Answer 5

Yes. As long as the pedestrian can take more information out of it.

At Dublin and Salzburg Airport quite a few pedestrian crossings display the remaining waiting time which leads the pedestrians to change their behavior.

Many villages put up signs at the road monitoring traffic speed immediately displaying passing by vehicles how fast they are going. img and source.

Although both can not directly be compared with each other - since one displays information and the other warns on wrong behavior - I strongly presume a connection since both trigger some sort of social acceptance I believe.

Also see or google for persuasive computing.