A traveler driving a Nissan Sentra north along Arizona State Route 89A on April 11, 2025, documented a journey from Sedona through the Oak Creek Canyon into Flagstaff, highlighting unusual state highway designations along the route. The trip covered the climb past red rock formations before the highway merged with Interstate 17 three miles south of Flagstaff.
Arizona Route 89A Ascent and Interstate 17 Merger
The drive began shortly after 6:00 a.m. in Sedona, utilizing a Nissan Sentra to drive through northbound traffic up State Route 89A. The route climbs out of the Oak Creek Canyon, transitioning from the lower canyon floor past a landscape of red rock formations and green pine trees. Approximately three miles south of Flagstaff, SR-89A terminates by merging with Interstate 17, creating a concurrent stretch of roadway that leads directly into the Flagstaff city center.
Upon arriving in Flagstaff at approximately 7:00 a.m., the traveler stopped to refuel the Nissan Sentra before proceeding toward subsequent destinations on the itinerary.
Geographic Anomalies of Arizona Interstates
The route highlighted distinct peculiarities within Arizona’s highway infrastructure, specifically regarding short intrastate routes bearing Interstate designations. Interstate 17 and Interstate 19 both operate entirely within the borders of Arizona and feature relatively short total lengths compared to cross-country national corridors.
While it does not cross state lines, it functions as a primary arterial connector linking two major designated transcontinental routes: Interstate 10 and Interstate 40.
Spanning approximately 63 miles, I-19 serves as a vital international trade corridor despite its short length. While transportation planners occasionally debate whether such localized routes warrant Interstate status rather than standard U.S. highway numbers, the numbering avoids conflicts within the Western region where north-south corridor options between I-15 and I-25 remain limited.