The cross walk timers are for walkers and when they hit "zero" it just means that walkers are not supposed to leave the curb because there is not enough time to cross the street before the traffic light lets the cars go thru. Councle Bluffs Iowa has countdown timers for some of the traffic lights for motor traffic so you know when the yellow & red light is coming up as you approach the green light. That way you know how long ya got to make the intersection before the light goes yellow/red. Most are located in the downtown district, they also use red light cameras there too to ticket drivers who run red lights.
Incorrect. The ones with the 10 second delay leave you just enough time to walk across the street if you hustle. The ones without a delay leave you stranded in the middle of the street when the light turns.
And every one I've every seen in other cities, the zero corresponds with the end of the green light. It doesn't really matter how they set them up, as long as they're all the same. But they sure as heck shouldn't make you guess or try to memorize every downtown intersection as to which timers are set up which way.