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Interstate 11 Corridor Tier I Environmental Impact Statement

The initial Interstate 11 (I-11) and Intermountain West Corridor Study was completed in 2014. This allowed I-11 efforts to move to the next phase, with projects and studies continuing in both Arizona and Nevada.

The Record of Decision and Final Preliminary Section 4(f) Evaluation (ROD) for the 280-mile I-11 study corridor – stretching from Nogales to Wickenburg – has been completed and published. After more than five years of study, technical analysis and input from communities and stakeholders, the publication of the ROD marks a major milestone as the final step in the Tier 1 Environmental Impacts (EIS) process, for this proposed highway corridor.

The signed ROD, approved by Federal Highway Administration (FHWA), is available on the Documents page. The ROD was prepared by the Arizona Department of Transportation and the FHWA and was completed in compliance with the National Environmental Policy Act. This decision document identifies the Selected Corridor Alternative, which is a Build Alternative. The Selected Alternative is a combination of new and existing roadways.

The Selected Corridor Alternative is the same as the Preferred Corridor Alternative outlined in the Final Tier 1 EIS and Preliminary Section 4(f) Evaluation (Final Tier 1 EIS) published on July 16, 2021. The Selected Corridor Alternative is a 2,000-foot-wide starting point within which the proposed I-11 facility could be built.

Interactive Map – Zoom in on a satellite view of the Selected Alternative.

In Nevada, the Regional Transportation Commission of Southern Nevada (RTC) led the effort to complete I-11 from US-95 to US-93 near the Hoover Dam Bypass Bridge, approximately 12.5 miles (Phase 1), while the Nevada Department of Transportation (NDOT) constructed the portion of I-11 from Railroad Pass to US 95, approximately 2.5 miles (Phase 2). Both phases were built simultaneously beginning in the spring of 2015 with construction completed in 2018.