Pedestrian crossing question ?

Question

In Britain, what determines how long it takes for the lights to stop the traffic after you have pressed the button? I find some are longer than others. Why not just stop the traffic as soon as the button is pressed?

Answer 1

On toucan and puffin crossings the lights are controlled by infa-red. If therre is still a person on the crossing then the lights will not turn green for the motorist

Answer 2

why would the world wait on you wait for the light like the cars have to... really... think about it what woul dhappen if the light changes every time someone push the button that wanted to across the road the cars might not never move.. pushing the button doesnt turn on the light it makes it stay on a bit long so ones can across

Answer 3

Because in some streets you would have major traffic queues and the odd pedestrian crossing every 10 seconds.  You have to try and time it to the users so everyone gets a fair wait.  Also, depending on the speed of the road, it takes longer at faster speeds to stop.

Answer 4

When I lived in Bristol I worked out that the length of time it took for the lights to stop the traffic after pushing the button was dependant upon the length of time since it was last pushed. ie - if someone had just crossed minutes before then you had a longer wait than if no one had crossed for hours

Answer 5

Depends on the engineer or local council.  Some are set so that if the button has not been pressed for more than a set time, the crossing will change immediately and then not respond again until the set time has again elapsed.  Others are set so that an additional delay is added before responding (so anyone near the crossing sees you press, will decide that they want to cross and come and wait next to you!).  Many crossings have radar sensors, small black boxes angled towards the cars to further delay response in heavy traffic.

Answer 6

There is no set time. There are sensors on the lights and they ensure there is a smooth traffic flow. If there is little, or no, traffic, then the traffic will stop quite quickly. If there is heavy traffic you will have to wait longer.

Answer 7

The city council determines this and to answer your second question......if the lights changed when the button was pressed just think of all of the accidents that doing this would cause.