Richard Kim wrote: "Ironically, no one complained when we increased the speed limits from 55 mph (88.5 kph)!"
Two things about that. First the symbol for kilometers per hour is km/h, as correctly shown on the inner scale of almost all U.S. speedometers. The letter p is the symbol for the prefix, "peta," which would make kph the non-SI value, "kilopetahours." Second, conversion of speed limits to SI would never be as precise as the value you indicate -- although I realize that you almost certainly wouldn't recommend the use of 88.5 km/h signs (as opposed to the more rational 90 km/h). I'd like to see 55 mph, 60 mph, 65 mph, 70 mph and 75 mph replaced by 90 km/h, 100 km/h, 110 km/h, 120 km/h and 130 km/h, respectively. If those states who now have a 75 mph top speed limit don't like 130 km/h, they can always opt for 120 km/h. (Interestingly, in Germany, 130 km/h is considered the appropriate speed [Richtgeschwindigkeit] for the Autobahns. However, on those stretches where speed limits are posted, anything over 120 km/h is rare.) Having said all that, let me be the first to welcome you to the USMA list. Bill Potts, CMS Roseville, CA http://metric1.org [SI Navigator]
