December 27, 2009: Just south of I-40, at the Flagstaff airport, former Alt US 89 merges with I-17. US 89 south of Flagstaff was decommissioned 20 years ago, even though the route through Prescott is far enough away from I-17 that there’s no reason it couldn’t have continued to exist.
Notice the three-digit width for the shield and the abstract representation of the Arizona state shape. Notice also the state name on the interstate shields.
This date has been used before, but photos at this interchange are the only 89 shields I have in the country.