The map shows the study area and a broader area where some related improvements may extend beyond the core corridor (courtesy of ADOT).
The Arizona Department of Transportation (ADOT), in cooperation with the City of Phoenix and the Maricopa Association of Governments (MAG), has begun a study of Interstate 10 (I-10) from the Deck Park Tunnel to the I-10/I-17 interchange (Split) near Phoenix Sky Harbor International Airport.
The study area also includes State Route 51 (SR 51) south of Thomas Road, the Loop 202 (Red Mountain Freeway) west of 24th Street and the entire interchange of I-10, SR 51 and Loop 202, also known as the “Mini-Stack,” given that traffic in this area is all interconnected.
This study takes a close look at one of the busiest stretches of I-10 in Phoenix to figure out how to make it safer, less congested and easier to access, especially for people going downtown or to Sky Harbor Airport.
This is one of the most complex and heavily used freeway areas in the state, ADOT said. This stretch of freeway affects commuters, airport travelers, downtown access, freight movement and more. This latest study builds upon previous work that began in mid-2023 and resulted in the release of the MAG Study, in January 2025.
ADOT is seeking input from the community to support the development of study alternatives. To take an online survey (available until June 30) and learn more, visit azdot.gov/I-10TunneltoSplit.
During this study, there will be additional opportunities for the public to provide input. In fall 2026, ADOT will hold a public meeting to share and seek input on the design alternatives. In late 2027/early 2028, a public hearing will be held to share and seek input on the draft Environmental Assessment. Both of these meetings will include an in-person meeting and a virtual meeting, along with a 30-day comment period.
