Are There Any Road Signs in the U.S. That Use Kilometers?

In 1975, U.S. President Gerald Ford signed the Metric Conversion Act into law, stating that the metric system had become the "preferred" way to measure weights and measures for all commerce and trade in the country. Looking around today, though, it's clear that the move didn't measure up, as no one wanted to give up the United States customary units that they found so familiar. Well, almost no one. Arizona took the bait, changing all of the signage on Interstate 19 -- 63 miles (101 km) from Tucson down to the Mexican border -- to metric. After it became apparent that no one else was following suit, Arizona wanted to change back, but it hadn't foreseen the head-on collision it faced with hotels, restaurants, and other businesses that were already using metric measurements in directing drivers to their establishments. Not to mention the cost of replacing approximately 400 road signs. Efforts got underway, stalled, started again, and stalled again. As of 2019, Arizona is still trying to revert back to the way the rest of America does it.

Life in the Grand Canyon State:

• Arizona is the only place in the world where the saguaro cactus grows; the plant can reach 40 feet (12.2 m) tall.
• Arizona's Grand Canyon is one of the designated "Seven Natural Wonders" of the world; it is the only one located in the United States.
• Arizona's climate is so varied that the state can sometimes boast both the hottest and coldest temperatures in the United States during a single day.