It doesn't work, or so I've heard. Drivers in those cities learn to expect the safety margin of the delay, and statistically they become more willing to run a red light right after it changes.
Back in the day they tried the overlapping red thing in my city. Once everyone got used to the new way of doing things the time when both light were red became a sort of anarchy zone. Everyone assumed that everyone else would strictly observe the red so they didn't have to.
I find myself reminded of an article about a German town that stripped out their lights and signs and just had everyone drive by basic priority rules. Apparently this sharply reduced incidents.
Some time ago I drove through that town without knowing anything about it. I didn't realize that they had such a concept, it just felt really stressful, because your normal expectations and intuitions don't apply.
This basic principle also explains why roundabouts (traffic circles) are so much safer than traffic lights. They feel unsafe to drivers, so they slow down and pay attention, instead of blindly trusting the lights.
In the UK, the lights go [red] → [red+amber] → [green], so that drivers are ready to move as soon as the light turns green. People don't run red lights.
What completely infuriates me is pedestrian crossings that don't automatically allow pedestrians to cross when the lights are in a state that would allow it.
Are you asking why peds are required to press a button at some intersections for a walk signal?
If so, consider that some intersections may require a long time (~45 seconds) for a ped to cross. When no one is crossing, this may be sub-optimal and a shorter time for that specific light combination should be used.
Nobody should have built an intersection anywhere that big, then. But such behaviors are totally infuriating in places where there are many pedestrians, for example all of the stations on the SF Muni's T-Third line require passengers to push the button to cross the street after disembarking at center platforms. These crossings are not far (only half of a moderately wide street) but they don't have a pedestrian walk phase by default. If you haven't pushed the button you get to just stand there for another cycle. Example:
As you can see, the street-view car has captured a brilliant scene. Traffic is jammed. Many pedestrians are waiting to cross. The guy in the Mini is either going to run the light or stop in the crosswalk. The person in the white minivan has somehow managed to drive up the street car tracks. And for the topping, someone has blocked the bike lane with a portable sign.
I'm asking why, if the lights will cycle in such a way that pedestrians COULD cross, why they should not automatically allow pedestrians to cross. It's infuriating to miss a cycle as a pedestrian, and whom does it benefit? I'm not suggesting that there not be buttons which can force a cycle or accelerate a cycle. How would motorists feel if traffic lights defaulted to red?
