You still have to do it for yourself

You know what I'm talking about.

Pedestrian crossings in the UK require you to push a button in order for the crossing to know you are there. At this point, there is a sign in bright orange that illuminates just above the button you just pushed that says PLEASE WAIT. Now, the traffic system chooses the right break in the traffic to turn the lights red and let you cross.

Straight forward, don't you think?

So why is it that, even though the PLEASE WAIT sign is illuminated, there are people on the crossing waiting and the system is it work, people still feel the need to push the button. Just in case. Just to make sure.

Irrational? Yes. Un-necessary contact with a button that lots of urine-soaked hands have pushed? Indeed.