ADOT reaches halfway point on $600M I-10 widening project in Tucson

Tucson drivers who use Interstate 10 southeast of downtown are about to see one of the project’s most consequential changes. The Arizona Department of Transportation has reached the halfway point of a $600 million reconstruction and widening effort between Kino Parkway and Alvernon Way, while permanently closing the Palo Verde Road interchange beginning Friday night. The closure will affect people traveling between central Tucson, south-side neighborhoods, businesses and the Kino Sports Complex, but it is necessary for crews to build additional freeway lanes, bridges and a replacement interchange nearby.

The three-mile project began in June 2025 and is expected to continue through 2028. ADOT describes it as the largest highway construction project in Southern Arizona history. The central goal is to widen I-10 to three lanes in each direction between Kino Parkway and Alvernon Way. The work is intended to ease congestion, improve safety and allow traffic to move more efficiently along one of Tucson’s busiest freeway corridors. During construction, ADOT has said it will maintain at least two travel lanes in each direction during peak periods.

The Palo Verde interchange will not be rebuilt. Instead, ADOT plans to open a new interchange at Country Club Road this fall, giving drivers access to the freeway route currently served by Palo Verde. The new Country Club interchange will use a diverging diamond design, a configuration that briefly moves traffic to the opposite side of the road. That arrangement allows vehicles turning onto freeway ramps to avoid crossing directly through opposing traffic, which can reduce conflict points and improve the movement of cars through the interchange.

The Country Club project will be only the second diverging diamond interchange in the Tucson area. The first opened at I-10 and Houghton Road in 2021. Before the new interchange can open, crews must continue demolishing sections of the existing freeway and constructing the lanes and bridges needed to support the redesigned roadway. The permanent Palo Verde closure is therefore a major transition in the project, changing how nearby drivers reach I-10 well before all of the broader improvements are complete.

Several other construction milestones have already been reached. Most of the pavement for the new Country Club interchange has been installed, and portions of the existing freeway have been removed to create space for new lanes. Crews have placed bridge girders for the reconstructed Kino Parkway interchange and are advancing new bridges over Palo Verde and Irvington roads. Work has also progressed on an undercrossing that will connect the north and south portions of the Kino Sports Complex, an important local destination for sports and community activities.

The project includes more than the three-lane expansion through the section between Kino Parkway and Alvernon Way. I-10 will be widened to four lanes in each direction west of Kino Parkway. ADOT also plans to build a new westbound on-ramp at the Alvernon interchange and reconstruct the existing Kino Parkway interchange. Together, those changes are intended to address bottlenecks and improve connections between the freeway and the surrounding streets, while the new sports complex undercrossing will provide a direct link beneath I-10.

The work is part of a larger effort shaped by an ADOT study completed in 2020. That study examined mobility needs along about 10 miles of I-10 between Interstate 19 and Kolb Road. It also identified an alignment for extending Barraza Aviation Parkway along Alvernon, creating a future connection between I-10 and downtown Tucson. ADOT has characterized the current project as the first in a series of improvements expected along the corridor, meaning the changes underway between Kino and Alvernon are being planned within a broader transportation strategy rather than as an isolated construction job.

The State Transportation Board awarded the design-build contract to Sundt-Jacobs. Earlier plans called for detailed designs to be shared with the public and for residents to speak with the design team at an open house. ADOT expects construction on the current project to remain active until 2028, with the Country Club interchange scheduled to open this fall. For Tucson residents, the immediate task will be adjusting to the Palo Verde closure and following changing traffic patterns as crews shift the freeway into its next phase. The long-term tradeoff is a wider, reconstructed I-10 with new connections, improved interchange layouts and additional capacity through a heavily traveled part of the city.