Trapster.com states that over 100,000 drivers are cited for speeding each day. From personal observation, many for going a traffic flow speed in places where the limit is absurdly low. (Illinois highways). People drive at a speed where they are comfortable driving at. Not many purposely speed for the thrill. A frustratingly low limit actually can be detrimental by causing unnecessary anger and road-rage plus drivers disrupting flow of traffic by going the limit. A uniform 75+ limit would keep more drivers legal and less anxious in a world where timeliness is a way of life. Remember, speed doesn't kill, inept drivers do. And speed isn't reckless driving. (DUI is)
(accommodations can always be made, a slow moving vehicle lane, variable speed limit systems, etc)