Why is there a delay after pushing the button at pedestrian crossings (in the UK)?

I’ve seen intersections where the ped lights are never lit unless the button is pressed (in the US), and others where they come on always. Possibly when the button is pressed, the cycle is altered to be pedestrian-friendly, like at a large intersection where additional time is allowed for slow peds to cross. Some intersections might not need that treatment.

Sometimes it’s force of habit. Sometimes the little light that tells you the button’s been pressed isn’t working.

And some people seem to believe that pressing the button multiple times will let the light know they really want to cross now.

I didn’t think they did, and I’m sure we don’t do things that differently in NI. I’ve stood at one or two traffic lights before thinking someone had pushed the “wait” button, when they just didn’t bother and we all waited like stooges.

I saw that this weekend, actually - group of young teen girls standing at an intersection with an active button, and they would press the button frequently, trying to disrupt the traffic flow along the major road.

As said above - it depends on the type of light. If it’s just a pedestrian crossing then, yes you do have to press the button. If it’s a light controlling a junction, however, in every case I’ve seen, the pedestrian signals light up anyway regardless of whether the button has been pressed (and, in my experience, the timing of the cycle is totally unaffected). The only bit that doesn’t light up in this second case is the orange WAIT sign above the button, if present.

The reason is simple, and clear:

People travel in packs. Packs, when walking along a pack, get separated. Where there is one person, there is likely to be another person following within 30 seconds or so: Think kids getting out of school, walkathons, families with kids running ahead, etc.

By instituting a pause before changing the light, you let the pack in the back catch up to the group in the front that pressed the button. Then, you only need to have one red light cycle on the road, rather than 2, when the light changes back to green for the cars before the second pack gets to the crossing. That’s what would happen with an instant “cross” signal.

So, the light is always green unless there is a pedestrian to push the button and give them a red light? How odd; those intersections in the US have no lights, just crosswalks drivers are supposed to yield to if someone is on them. I suppose that would make things a bit safer than here, where people occasionally hit pedestrians in crosswalks.

I realise there are different types of lights, but I’ve never seen the action described above. Perhaps Belfast just isn’t busy enough to require such a system, or that pedestrians approach and push wait regardless. But I’ve always had to push wait to cross and when driving I’ve never noticed crossings showing green for pedestrians until one approaches and (I assume) presses wait.

These lights exist in the US. Usually they take the form of a flashing green light. The pole supporting the signal will have a red-yellow-red ring around it, as well.

From wikipedia:

Here (I hope) is a street view example of a red-yellow-red light in Salem, MA. The other side of that signal has a flashing green. This intersection ONLY changes to red on pedestrian request.

Street View

Interestingly (or not), the flashing green and the pole-banding are no longer mentioned in the Massachusetts RMV handbook. They certainly were in there 12 years ago when I took the test. I guess they’re being phased out.

Here is an example in Street View of a crossing in London (one I pass every day in the way to work) which is part of the lights controlling the junction. The traffic lights are on green currently, so the red man is showing regardless of whether anyone has pushed the button.

This one, on the other hand, is totally pedestrian controlled. The lights are always green until someone presses the button (which, as it’s right outside Waterloo station, happens fairly frequently!). Now that I come to think of it, I’m not sure if the red man symbol is always lit up, or only lights when someone presses the button but it’s not yet safe to cross.

Forgot about streetview! Thisis the particular crossing I was annoyed with that prompted the OP. A main road, but not all that busy. I walked up to it this evening, it was in view for maybe 5 minutes and no-one used it in that time (in fact I’ve never seen anyone use it except myself). I had to wait 39 seconds after pressing the button for the lights to change.

I think one difference to keep in mind is that in most places in the US (I’m thinking of cities with a systematic grid pattern), pedestrians typically have fairly decent line of sight at the crossing because the roads are usually pretty straight. In the UK and many other places though, roads tend be winding, and often times with complicated junctions at odd angles and numerous obstructions that make it difficult for pedestrians to see the traffic. I think this may help explain why this kind of crossings is much more common in the UK than in the US.

Those certainly exist in California. Here’s a street view link to one along the Great Hwy in San Francisco. However, if I remember correctly this one does not have buttons but rather some sort of pedestrian sensor. There are others with buttons, but I can’t immediately recall where.