Legal terms relating to transit (MPH) in US are in miles. Measurements are in whatever you want. So there is a bias toward using Miles in general, when talkin

Legal terms relating to transit (MPH) in US are in miles. Measurements are in whatever you want. So there is a bias toward using Miles in general, when talking about ~distance~ whether or not you measure in MM or Inches. Wrenches for fasteners, as an example, are not an official decision. The UK also does this. They actually use the metric for most measurements, but their roadways etc. are in miles. so its not just a US thing.