In California at least - the speed limit cannot be different (more than some statistical measure) of the real world speed people actually drive on the road. Th

In California at least - the speed limit cannot be different (more than some statistical measure) of the real world speed people actually drive on the road. Theres a process for requesting a survey of actual vehicle speed for a street. If the measures speeds differ in a statistically significant way from the posted speed limit, the posted speed limit has to be changed.