“Standards for the exact length of an inch have varied in the past, but since the adoption of the international yard during the 1950s and 1960s the inch has been based on the metric system and defined as exactly 25.4 mm.”
“Standards for the exact length of an inch have varied in the past, but since the adoption of the international yard during the 1950s and 1960s the inch has been based on the metric system and defined as exactly 25.4 mm.”
We could start by having both on new signs. Over many years the majority of signs would eventually have both. Then, maybe 15 years from now, we could drop the imperial measurements from all new signs. I think that would help with cost.
(Adjust timeframe based on the average useful life of a sign plus an extra margin.)