Originally Posted by Escape_Driver
WOW I just found something out Look at this
Section 2B.13 of Federal Highway Administration manual recommends setting scientifically reasonable limits for all types of roads, then enforcing the limits with narrow tolerance.
Specifically, Section 2B.13 says limits should be set within 5 mph of the speed used by 85 percent of motorists traveling in free-flowing traffic. This approach, said a federal study - RD-85/096 - produces speed limits that are acceptable to a large majority of motorists and achieve the lowest accident risk.