I think they do care about people running red lights, that's why they're taking the cameras down.
People speed up when the light turns yellow so the camera won't catch them in the intersection when the light turns red. Cameras sounded like a good idea, but they actually caused an increase in accidents.
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Actually, there's no data whatsoever to show people speeding up to beat the yellow to any greater degree than they ever did. Your best bet, anyway, is to come to a stop IN the intersection and just sit there through the redcycle.