I agree that kilometers or miles per hour are more useful. Perhaps more important: FMVSS101 requires MPH and allows km/h markings CMVSS101 requires km/h and allows MPH markings
Since neither mentions m/s and both state what they allow as well as what they require, it is not clear to me that m/s would be legal. As well trained (but now retired) engineering employee of a motor vehicle manufacturer, I can tell you step 1. If there really appears to be any demand (I think VERY little), get the company lawyers to write to NHSTA (and the corresponding Canadian agency) for a private interpretation. Without that interpretation, "ain't happening." Units that don't correspond to posted speed limits don't make a lot of sense. The entire system would have to be changed, and these units (m/s) would seem "unnatural" to most. --- On Sun, 3/15/09, Carleton MacDonald <[email protected]> wrote: > From: Carleton MacDonald <[email protected]> > Subject: [USMA:43945] Re: wind velocity > To: "U.S. Metric Association" <[email protected]> > Date: Sunday, March 15, 2009, 7:21 PM > For vehicle speed, km/h is easier to deal with because road > distances are in > km and this helps you estimate when you will get there or > how long it would > take. Distance 250 km, speed 80 km/h, it will take a bit > over three hours. > > Carleton > > -----Original Message----- > From: [email protected] > [mailto:[email protected]] On Behalf > Of [email protected] > Sent: Sunday, March 15, 2009 11:57 > To: U.S. Metric Association > Subject: [USMA:43888] Re: wind velocity > > > Mark, > > Just as you do now, I have long advocated the SI unit of > speed, m/s, for > wind speed as well as for vehicle speed, for reasons of > safety and > metrication. > > Unfortunately, it is necessary to cement m/s tick markers > on an analog > speedometer, and no recourse for digital displays, until > manufacturers > provide a m/s option. > > Is m/s an option already in *any* vehicle instrument > cluster? > > Gene. > > ---- Original message ---- > >Date: Sun, 15 Mar 2009 04:04:24 -0800 > >From: Mark Simon <[email protected]> > >Subject: [USMA:43871] wind velocity > >To: "U.S. Metric Association" > <[email protected]> > > > > > >The weather report predicts there will be a west wind > with velocity of > >28 km/h. I am going to ride my bicycle about 18 km > towards the west > >today. I cannot visualize 28 km/h, but I can visualize > 7.8 m/s. This > >means to me that I will get a better workout, going to > my destination, > >and should have an easier ride home. Would somebody > please explain the > >logic of measuring velocity in km/h? I do not > understand why this is > >done. I live in Southern California, and traffic is > unpredictable > >here. When I drive, I am only concerned with safety, > and leave > >additional time to get to my destination. If were are > going to convert > >to the metric system in the United States, why not > consider using m/s > >as the basic unit? I am usually only concerned with my > velocity when > >the traffic light turns yellow in front of me, and I > have to make a > >decision whether to decelerate or continue driving. If > my velocity is > >measured in m/s, that would make calculations simpler. > In Europe, with > >its denser populations, does measuring velocity in km/h > work well in > >calculations? I wager that highways are engineered > using m/s > >calculations. > >Is it possible to get a velocimeter for a bicycle that > measures in m/s? > >
