Initial work starting on Loop 303 and I-17 improvements in north Phoenix

With plans for the Loop 303 Improvement Project in north Phoenix on the drawing board in recent years, one of the most frequent questions ADOT has fielded is: When are you guys going to build direct ramps connecting Interstate 17 and the 303?

It’s nice to be able to say “the answer is now!” That’s right, construction of the $129 million Loop 303 widening project between I-17 and 51st Avenue is now underway.

A major component of the work will be building the direct ramps to create the freeway-to-freeway interchange. When completed over the next two-and-a-half years, drivers will skip the traffic signals at the current diamond interchange.

Crews have installed temporary barrier walls along I-17 exit ramps and elsewhere in the area as construction work zones take shape. 

Initial work will focus on creating foundations for ramps and bridges. Likely the most noticeable feature of the project will be construction of an elevated flyover ramp that will carry northbound I-17 traffic directly onto westbound Loop 303.

The project also will expand Loop 303 from two to three lanes in each direction between I-17 and 51st Avenue. This video simulation shows what’s coming.   

ADOT will keep you posted on closures or major ramp or lane restrictions needed as the project advances. As always, we ask that if you’re driving in the area please stay alert and take your role in keeping work zones seriously. That means slowing down and looking out for construction crews and equipment.

A key reason ADOT is able to start construction of this Loop 303 project is that Maricopa County voters approved Proposition 479 in 2024. It’s the first project to be built under the Maricopa Association of Governments’ Proposition 479 freeway plan, which includes funding from a half-cent sales tax for regional transportation projects.

For more information about the Loop 303 improvements visit azdot.gov/L303LakePleasantI-17.