[citation needed] Loop 303 currently begins at Van Buren Street, one mile south of I-10 in Goodyear.

[2] South of Van Buren Street it continues as Cotton Lane but without a route number.

It then proceeds through a farmland terrain and passes by the Wildlife World Zoo near the Northern Parkway trumpet interchange.

[citation needed] After passing Northern Parkway, the freeway continues for a few miles before entering a residential community at Greenway Road and turning northeast.

[citation needed] Maricopa County took charge of SR 303 when it was dropped from the regional freeway plans in 1995, maintaining the interim two-lane highway along the original corridor while keeping the state route designation.

[citation needed] As Maricopa County had completed much of the required study and preparation work, construction on the freeway proceeded from the I-10 to I-17 segment.

[9] According to an agreement between the state legislature and ADOT, Statewide Transportation Acceleration Needs (STAN) funds were used to build a partial interchange at Bell Road in summer 2010, several years before previously intended.

Motorists still have to pass through signaled ramp junctions at I-17 until a full freeway-to-freeway interchange is built projected to begin in 2028.

[9][11] Beginning in mid-2011, ADOT began upgrading Loop 303 between US 60 and I-10 from a two-lane highway to a six-lane freeway with auxiliary lanes and interchanges.

In August 2011, construction began on the six-mile segment between Mountain View Boulevard and Peoria Avenue.

This segment was completed in fall 2013 with interchanges at Bell, Greenway, Waddell, and Cactus Roads as well as Peoria Avenue.

[15][16] In August 2014, construction began on the seven-mile segment between US 60 and Happy Valley Parkway to upgrade it to freeway standards.

Construction was complete in October 2017 with the opening of all of the south half ramps along with the Van Buran Street interchange.

[11] Long-term plans include the Loop 303 to continue south of SR 30 to the future I-11 Hassayampa Freeway.