Plans to expand 26 miles of Interstate 10 between Phoenix and Casa Grande are moving forward following environmental approval late last week. The widening project will increase capacity and reduce congestion on a busy section of I-10 near Wild Horse Pass within the Gila River Indian Community.

A key segment slated for improvement is the I-10 Gila River Indian Community Project, a nearly 12-mile section from Loop 202 (Santan/South Mountain) to just north of the Gila River Bridges. A portion of the segment is within the Maricopa Association of Governments (MAG) region, which includes state and federal funding and more than $220 million in funding through Proposition 400 – the dedicated half-cent sales tax for transportation funded by Maricopa County voters.

Other corridor improvements that are part of the I-10 Wild Horse Pass Corridor include widening 13 miles of roadway from south of the bridges to State Route 387. Funding for the remaining 13 miles south of the bridge are made possible by state and federal funds, plus a $95 million federal grant awarded in January.

Additional improvements within the corridor that were not part of this federal environmental assessment are the removal and replacement of the I-10 Bridges Over the Gila River Project to modernize a key piece of infrastructure. The bridge project is expected to begin construction this spring and is funded by state and federal funds.

Environmental Approval

The Final Environmental Assessment (EA) and the Final Design Concept Report (DCR) have been prepared and will be made available to the public for 30 days. After this 30-day period, in approximately April of this year, ADOT is anticipated to sign the Finding of No Significant Impact (FONSI). The Arizona Department of Transportation prepared the Final EA in compliance with the National Environmental Policy Act (NEPA).

The final documents include comments made by community members during the public comment period, which lasted 51 days and included four public hearings in the fall of 2022. The environmental approval documents are available on the project website.

The Environmental Assessment was completed in cooperation with the Gila River Indian Community and MAG. The Gila River Indian Community approved the release of the documents during a Community Council meeting last week. Governor Stephen Roe Lewis has identified the Wild Horse Pass improvements as a key priority for his 100-Day Plan for his newest term in office.

Major Project Benefits

The proposed improvements will provide local, statewide, and national benefits. As the main roadway between metro Phoenix and Tucson for commuters, cross-country travelers and commercial traffic, I-10 is a Key Commerce Corridor for Arizona and the U.S.

The proposed improvements will enhance the reliability of the freight traffic in the corridor, which provides connectivity to Mexico and the ports of southern California. Locally, the route serves the Gila River Indian Community by providing connections to employment, medical, educational and other critical services both within and outside of the Community.

Capacity and Safety

The proposed improvements include adding a new general purpose lane in both eastbound and westbound directions, extending the High Occupancy Vehicle (HOV) lane on I-10 from Loop 202 to Riggs Road, and improving interchanges and crossroads to increase capacity and access. This will also improve safety by reducing congestion and travel times and lessening detoured traffic on the Gila River Indian Community.

Other improvements include new and improved traffic interchanges to create safer crossings for farm equipment, bicyclists and pedestrians, and the installation of fiber optic infrastructure within the ADOT right of way to allow for the installation of sensors, cameras and other highway safety-related technology.