Others have pointed out the revenue centered yellow light shortening. Some dangers born from this are panic stops and slow, generally erratic traffic leading up

Others have pointed out the revenue centered yellow light shortening. Some dangers born from this are panic stops and slow, generally erratic traffic leading up to intersections with known red-light cameras. The camera effectively changes the perception of the yellow light from "prepare to stop, if it is safe" to "stop right now or risk a $75+ fine" (Where I live the fine will surely have doubled at least once by the time you actually get the ticket in the mail, but that's another issue). I've often wondered if the folks implementing the cameras have thought about how the combination camera-driven paranoia, shortened yellows and altered perception of yellows will impact the traffic flow. If upstream light-timings aren't adjusted to account for the camera bottleneck, problems are inevitable.