aggemamme

ahaha.

Even at 'lone' pedestrian crossings with no other roads, there is usually a delay from you press the button until the pedestrian signal will turn green. The delay seems unnecessary, but why is it there?

To discourage kids from playing with it (they don't get satisfying immediate feedback that they can 'control traffic')?

Are any other mechanisms ever used for vehicle detection?

Do you know of any traffic light systems that are 'online', i.e. could be controlled by a central "command centre"?

Some time ago I heard about GPRS (GSM) enabled signalling systems which could be dynamically altered from central control, in order to adapt to changing traffic patterns, etc.

In that case, have there ever been any vulnerabilities in such systems?

How's the wiring normally done? Is there one big relay box for the whole intersection, or do each lone signal communicate and keep in sync with the others?

I think temporary construction signals (for when two lanes narrow into one lane, which cars alternatively have to use) use radio to communicate, right? Or maybe just accurate clocks?