Don Boudreaux at Cafe Hayak tells this story:
There it was, in big, bold, black and white: “SPEED LIMIT 65”And then opines:
As I drove on Saturday to a conference, signs with this crystal-clear message were displayed prominently along I-66, I-81, and I-64 in Virginia. And yet I disobeyed this command not to drive at speeds in excess of 65 MPH. I set my cruise-control on 73 (just shy of ten-miles per hour over the posted speed limit), kept it there, and enjoyed the drive. I even passed three or four patrol cars lying in wait for speeders. Not one pursued me.
This everyday driving experience and my mental experiment confirm that law is not just what the state says it is and only what the state says it is.Except when the state wants it to be exactly what it says it is.
Law is much more nuanced, rich, and spontaneous than the state’s written rules.But not near as nuanced, rich and spontaneous as it was prior to the state writing this precise law.
The real law on U.S. highways is something like the following: if weather conditions are decent and if traffic is not too heavy, then you can drive between five and ten miles per hour over the posted speed limit.Which is not near as nuanced, rich and spontaneous as what used to be the law in many jurisdictions, e.g., Washington:
No person shall drive a vehicle on a highway at a speed greater than is reasonable and prudent under the conditions and having regard to the actual and potential hazards then existing.And then came maximum speed limits.
Back to Don:
No one legislated this rule; it’s not written down in any official statute book; it’s certainly not posted along highways. It evolved spontaneously from everyday practice and is now part of the expectations of all drivers — and, importantly, it is also part of the expectations of highway patrol officers.This does seem to reflect everday practice. But both the law and the practiced rule represent a devolution from the days of no written maximum speed limits. And, in many cases, this cushion may exist via legislative intent as the penalties available for minor speeding infractions are nominal and enforcement is viewed as a poor use of officer’s time both from the perspective of revenue generation and highway safety. They want the big ticket reckless speeders as defined in their respective state statutes.
There is a fairly detailed review of state speeding laws here.