Well, the law would let Arizona do whatever the hell they want. Unfortunately, they apparently want Customary. Road signage is controlled by the MUTCD (Manual for Uniform Traffic Control Devices). In the spirit of "perfect duality" the Federal government allows the signs themselves to be of either metric or Customary dimension (but specific sizes) and to convey either metric or Customary information, but in specified formats. The States have to adopt the MUTCD in its entirety, or establish "substantially similar" rules of their own. Without getting into how many lawyers can dance on the head of a pin, several States have said "no" to metric, and only use the Customary part of the MUTCD. The Feds refuse to force metric either in signage or in highway construction. The only solution is to have a backbone and fix the system of weights and measures. However, Congress has obviously chosen to fix it as "Hey, there's metric and there's Customary. Use whatever the hell you want."
--- On Sat, 5/30/09, Pierre Abbat <p...@phma.optus.nu> wrote: From: Pierre Abbat <p...@phma.optus.nu> Subject: [USMA:45139] Re: News : ADOT defends replacing metric signs along I-19 : Nogales International : Nogales, AZ To: "U.S. Metric Association" <usma@colostate.edu> Date: Saturday, May 30, 2009, 1:19 AM On Friday 29 May 2009 19:22:59 John M. Steele wrote: > "Preferred" and 50 cents might buy you coffee. > > You need words like "these and no other" or one is "legal", the other is > "illegal" to mean anything. I think you misunderstood me. My point is not that the federal government ought to abolish English units, or that it has not done so; it is that the Arizona law violates the hierarchy established by the Constitution, which is that powers not delegated to the federal government are retained by the states or the people. Arizona therefore has the power to design and label roads (except for "post Roads", which are within the power of the FG) in metric, without waiting for the FG to mandate it, or for any other state to do it first. And it ought to do so. Pierre
