> People go through yellows because that is legal to do.
IIRC (and this may vary state to state), it actually isn't legal to go thru a yellow. From what I recall (and I'll admit I may be wrong), the actual law is that if you are before the "stop line" or intersection, and the light turns yellow, you are supposed to come to a complete stop. If, however, you are already in the intersection (your front bumper is beyond that "line"), you can proceed with caution, provided you clear the intersection before the light turns red.
Again - I may be wrong about this, and concede that it could vary across jurisdictions.
IIRC (and this may vary state to state), it actually isn't legal to go thru a yellow. From what I recall (and I'll admit I may be wrong), the actual law is that if you are before the "stop line" or intersection, and the light turns yellow, you are supposed to come to a complete stop. If, however, you are already in the intersection (your front bumper is beyond that "line"), you can proceed with caution, provided you clear the intersection before the light turns red.
Again - I may be wrong about this, and concede that it could vary across jurisdictions.