Westbound Loop 303 will narrow to one lane between Interstate 17 and 43rd Avenue beginning at 5 a.m. Wednesday, Sept. 9, with the restriction scheduled to last through October.
The Arizona Department of Transportation expects substantial delays, particularly where drivers leave northbound I-17 for Loop 303 and Sonoran Desert Drive. Bridge construction is prompting the restriction, according to ADOT’s Sept. 2 announcement.
Drivers approaching from northbound I-17 can exit at Dove Valley Road, head west, then turn south on 43rd Avenue to reach westbound Loop 303 beyond the restricted segment. That route gives motorists heading toward the Northwest Valley an alternative to the interchange bottleneck.
Full closures also scheduled
The lane reduction comes alongside several overnight and weekend closures listed on ADOT’s project page:
- Sept. 8-9: Westbound Loop 303 between I-17 and 43rd Avenue closes from 9 p.m. Tuesday to 5 a.m. Wednesday. The northbound I-17 exit for Loop 303 and Sonoran Desert Drive also closes.
- Sept. 9-11: Westbound Loop 303 closes at 43rd Avenue overnight, from 9 p.m. to 5 a.m., ending Friday morning.
- Sept. 11-14: A continuous westbound closure at 43rd Avenue runs from 10 p.m. Friday to 5 a.m. Monday.
For the closures at 43rd Avenue, ADOT directs drivers off the freeway and back on using the interchange ramps. The agency lists a 45 mph speed limit in the long-term work zone.
Part of a $129 million interchange project
The I-17/Loop 303 work includes direct freeway-to-freeway ramps and an additional lane in each direction between I-17 and 51st Avenue. ADOT puts the project’s cost at $129 million and its scheduled completion in 2028.
ADOT identifies it as the first Phoenix-area freeway project funded under the Proposition 479 regional transportation plan, approved by Maricopa County voters in 2024. The funding includes the county’s half-cent transportation sales tax.
Closure schedules can change. Check ADOT’s linked project notices before traveling.
Featured photograph: Loop 303 at 43rd Avenue on Nov. 5, 2023. This archival image predates the current work. Photo by Hunter Trick, via Wikimedia Commons, licensed under CC BY-SA 4.0. Resized for display.
