ADOT opens Diverging Diamond Interchange at I-10 and Miller Road

Reconstruction of interchange in Buckeye part of I-10 widening project

I-10MillerRoadDivergingDiamondInterchangeOpenAug2322ADOTphoto2.jpgPHOENIX – Drivers in the West Valley now have a reconstructed interchange to use along Interstate 10 in Buckeye as the Arizona Department of Transportation moves forward with an ongoing I-10 widening project.

All ramp connections at I-10 and Miller Road have been opened as a Diverging Diamond Interchange (DDI) following reconstruction work that started in January.

ADOT is widening 8 miles of I-10 from two to three lanes in each direction between Verrado Way and State Route 85 while also reconstructing the interchanges at Miller and Watson roads. The entire $82 million I-10 improvement project, which was launched in July 2021, is on schedule for completion in summer 2023.

The I-10/Miller Road interchange is the third full diverging diamond to be added along the state’s highway system. DDIs also have been constructed at I-17 and Happy Valley Road in north Phoenix and along I-10 at Houghton Road in the Tucson area.

Diverging diamonds, which have grown in popularity across the country, allow the two directions of cross-street traffic traveling over or under a freeway to shift to the opposite side of the roadway. The crossing is designed to improve the overall movement of traffic and enhance safety by limiting potential traffic conflict points and allowing direct left turns onto a freeway entrance ramp. Drivers avoid waiting at a traffic signal or crossing in front of opposing traffic when making those left turns.

Crews on the current I-10 project in Buckeye are slated to ramp up the reconstruction of the Watson Road interchange as a DDI this fall. Drivers can expect temporary ramp closures and restrictions along Watson Road at I-10 as the work moves forward. 

ADOT plans and constructs new freeways, additional lanes and other improvements in the Phoenix area as part of the Regional Transportation Plan for the Maricopa County region. Projects are funded in part by Proposition 400, a dedicated sales tax approved by Maricopa County voters in 2004.