About thirty years ago, America tried to go global by integrating the metric system and...we all know how that turned out. Oddly enough, there are still some American places out there that use metric measurements (not just those bad people dealing in kilos...).
One such zany region is the American southwest, where Interstate 19 measures its exit intervals in kilometers. After years of quirk, I-19's signs have gotten old and worn and now need to be replaced with new, more reflective units.