"The posted speed must be within 5mph of the average drivers speed during the speed study. For instance, if the speed study shows that the average speed driven on a road is 41 mph, then the posted speed must be 45mph (41mph rounded up to the nearest 5mph or 45mph). The speed can only be rounded up. Many speeding tickets will fall to this one. "
If that is the case why is the speed limit not 80 on the freeway? Who doesn't drive 80 on the freeway? Even in the slow lane you'll get traffic behind you at 70 (excluding large trucks). I know there are some exceptions to people driving above 70 but they should be weighed out by the people that drive above 80.