Metric works in the US where it was practical and was cheap to switch out to use it. In many instances it does not really mater. In some instances it is histo

Metric works in the US where it was practical and was cheap to switch out to use it. In many instances it does not really mater. In some instances it is historical (such as property and distance). Metric is also a historical thing. The US basically came along and mandated it for most other countries that had recently been destroyed in WW2. It was a good time to 'reset' and get things changed over. The US planned on doing it too but found other uses for the money allocated to do it. This sort of argument is the same as with CO2 emissions. When it is cheaper to switch over the US will do it. You will have to justify switching out billions of dollars worth of signage, inconveniencing millions of people to do it, millions of man hours to switch out docs and change one number from something to another, other than some notion of 'its better'. It can be done however, this is not a cheap thing people are asking for.