[Ed. – I mean, if it messes with engineering a high-speed rail system, you know it’s got to go.]
Some land surveyors use what’s known as the U.S. survey foot. Others use the definition that’s more accepted by the broader world: the international foot.
The difference between them is so tiny that you can’t see it with the naked eye on a 12-inch ruler. But over big distances, it matters. So, to reduce the chance for errors and confusion, the federal government has announced it’s finally giving the boot to the survey foot.
The international foot is the smaller one — adding about an eighth of an inch of difference when measuring a mile. That means the United States is 28.3 feet wider when measured using the international foot instead of the survey foot.
The change started in 1959, when the federal government mandated that everyone use the international foot but allowed surveyors to keep to the old U.S. survey foot for a while. That temporary reprieve has lasted 60 years, but it will finally end in 2022, the National Oceanic and Atmospheric Administration and the National Institute of Standards and Technology announced in October.