What's wrong with timing of lights? I know that the lights along 19th Ave in San Francisco are timed and it's posted what they are timed at. I seem to recall that they are set slightly below the speed limit but my memory may be faulty. Bottom line - during "rush" hour, traffic flows smoothly because all the commuters know how to drive to stay with the lights, at other times, it can be a nightmare as "regular folk" don't pay as much attention and continue to race up to the red lights