I agree Mike that there should NOT be both English and metric road
signs as it would be very unsafe. Pasting over current signs with
metric is a good way to begin; however, the US should adopt the
international sign/symbol for speeds and speed limits. The sign is
round with a number in the middle. The would save on expensive
aluminum material. The "km" could be placed in small letters at
the bottom of the circle beneath the number to help avoid confusion.
With examples of the US standard for metric speed limit signs being
shown here
http://mutcd.fhwa.dot.gov/HTM/2003r1/part2/fig2b-01_longdesc.htm
wasn't the original plan to use a red circle, rather than a black
one, but it was
changed (to a green circle at one point, no)? The red circle would
have made the
sign look a lot more like the internationally used speed limit sign.
