Untold Arizona: How Arizona's Metric Highway Nearly Lost Its Unique Status
Out of nearly 47,000 miles that make up the nation’s interstate system, Arizona stands out. Specifically, a 63-mile stretch in the southern part of the state. Interstate 19 is the country’s only continuous highway that lists distances in kilometers, not miles. Starting just north of the border at Nogales, Interstate 19 stretches 101 kilometers to Tucson.
