Check this out. I was searching through some Federal Regulation Code...I
was looking for an automotive law in particular. In browsing I noticed
that the entire document was in metric first with english in parenthesis...
An example...
General requirements for trailers and semitrailers
manufactured on or after January 26, 1998. Each trailer and semitrailer
with a gross vehicle weight rating of 4,536 kg (10,000 pounds) or more,
and manufactured on or after January 26, 1998, must be equipped with a
rear impact guard that meets the requirements of Federal Motor Vehicle
Safety Standard No. 223 (49 CFR 571.223) in effect at the time the
vehicle was manufactured. When the rear impact guard is installed on the
trailer or semitrailer, the vehicle must, at a minimum, meet the
requirements of FMVSS No. 224 (49 CFR 571.224) in effect at the time the
vehicle was manufactured. The requirements of paragraph (a) of this
section do not apply to pole trailers (as defined in Sec. 390.5 of this
chapter); pulpwood trailers, low chassis vehicles, special purpose
vehicles, wheels back vehicles (as defined in Sec. 393.5); and trailers
towed in driveaway-towaway operations (as defined in Sec. 390.5).
(2) Impact guard width. The outermost surfaces of the horizontal
member of the guard must extend to within 100 mm (4 inches) of the side
extremities of the vehicle. The outermost surface of the horizontal
member shall not extend beyond the side extremity of the vehicle.
(3) Guard height. The vertical distance between the bottom edge of
the horizontal member of the guard and the ground shall not exceed 560
mm (22 inches) at any point across the full width of the member. Guards
with rounded corners may curve upward
[[Page 1039]]
within 255 mm (10 inches) of the longitudinal vertical planes that are
tangent to the side extremities of the vehicle.
(4) Guard rear surface. At any height 560 mm (22 inches) or more
