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Interstate 11 Corridor Tier 1 Environmental Impact Statement, Nogales to Wickenburg
Interstate 11 Corridor Tier 1 Environmental Impact Statement, Nogales to Wickenburg


Fact Sheets

Project Fact Sheets will added as they become available.

Project Fact Sheet - Spring 2017
Winter 2018

Project Fact Sheet - Spring 2017 Spanish
Winter 2018 - Español

Project Fact Sheet - Spring 2017
Spring 2017

Project Fact Sheet - Spring 2017 Spanish
Spring 2017 - Español

Project Fact Sheet - Spring 2016
Spring 2016

Project Fact Sheet - Spring 2016 
Spring 2016 - Español




This three-year environmental study, initiated in early 2016, will be completed in accordance with NEPA and other regulatory requirements, to consider possible I-11 corridor routes for the approximate 280-mile area between Nogales and Wickenburg. The first step is developing an ASR that will assess a wide range of corridor alternatives and options, along with opportunities and constraints. Subsequently, a Tier 1 EIS will evaluate in greater detail a smaller number of corridor alternatives, including segments that may advance as independent projects. These corridor alternatives will be evaluated against a No Build Alternative, also known as a “do nothing” alternative.

NEPA was enacted by Congress in December 1969 and signed into law in January 1970, establishing the broad national framework for protecting our environment. NEPA's basic policy is to assure that all branches of government give proper consideration to the environment prior to undertaking any major federal action that significantly affects the environment. Under NEPA, federal lead agencies, such as FHWA, are required to consider impacts of a proposed action on social, cultural, natural, and economic resources.

The environmental review process under NEPA also provides an opportunity for you, the public, to be involved in the decision-making. It helps you understand what is being proposed; allows you to offer your thoughts and ideas on alternative ways to accomplish what is being proposed; and seeks your comments on the potential environmental effects and possible mitigation required for the proposed action.

For more information on the environmental assessment to be completed for an EIS, visit the Environmental Process page.

An EIS is a document prepared to describe the effects for proposed activities on the environment, defined as the natural and physical environment, and the relationship of people with that environment. An "impact" is a change in consequence that results from an activity. Impacts can be positive or negative or both. An EIS describes impacts, as well as ways to "mitigate" impacts, or lessen or remove negative impacts.

In a Tier 1 EIS process, an agency prepares a document that analyzes a program, large project, or undefined corridor on a broad scale. This current study is undertaking a Tier 1 EIS due to the large study area (approximately 280 miles in length) and undefined nature of the corridor.

A Tier 2 environmental document involves a specific project and applicable NEPA class of action that could include an EIS, Environmental Assessment (EA), or Categorical Exclusion (CE).

A Draft EIS will publish the Purpose and Need for the I-11 Corridor, evaluate potential impacts of each corridor alternative, and identify a Preferred Corridor Alternative. The Draft EIS will be made available for public review and comment in 2018 through a series of public hearings and 45-day comment period.

Upon completion of the public hearings, the study team will incorporate comments and responses into a Final Tier 1 EIS, conducting any further analysis, as necessary. This document will include a phased implementation plan to guide implementation of the Selected Corridor Alternative through future environmental reviews. FHWA will issue a ROD upon acceptance of the Final Tier 1 EIS. The ROD formalizes the official decision on the Selected Corridor Alternative. A ROD is anticipated to be issued in 2019.

This is one of the topics that the I-11 Corridor Tier 1 EIS will determine. A 2,000-foot study corridor is used during this early stage of alternatives analysis to identify the broad route of travel. The actual transportation facility proposed will have a much narrower footprint, however may be placed at varying locations within the 2,000-foot corridor to avoid constraints like mountains or buildings.

The vision for I-11 is for a multimodal facility, however, investigation in developing the Purpose and Need for this corridor segment (Nogales to Wickenburg, Arizona) identified no specific or immediate need for additional rail and/or utility facilities in the Corridor Study Area right now. Engineering will be based on design criteria for a proposed interstate facility, while also allowing for future development of other multimodal elements (e.g., smooth enough terrain for freight rail). Therefore, if a utility or railroad company would like to build a parallel facility to the roadway in the future, they will not be precluded by engineering constraints.

Currently, a north-south freight rail corridor parallels Interstate 19 between Nogales and Tucson (Union Pacific Railroad [UPRR] Nogales Subdivision), which connects to UPPR’s southernmost mainline corridor in the US. This mainline, generally running east-west between Los Angeles, California and El Paso, Texas partially runs north-south through the I-11 study area where it parallels Interstate 10 between Tucson and Casa Grande. Burlington Northern Santa Fe maintains freight rail service along US 60 (north portion of study area, connecting Interstate 40 to the Phoenix metropolitan area via Wickenburg).

ADOT recently received a Record of Decision from the Federal Railroad Administration after completing a Tier 1 Environmental Impact Statement that considers passenger rail between Tucson and Phoenix. A potential passenger rail route falls within the broad I-11 study corridor, connecting travelers in these two major population centers. For more information on this corridor, see:

The Tier 1 EIS will provide a roadmap for advancing smaller, individual projects through Tier 2 environmental reviews. During the Tier 2 environmental process, ADOT and FHWA will conduct additional environmental and engineering studies examining individual projects within the Selected Corridor Alternative in greater detail.

Interstate 11 Tier 1 EIS Study Team
c/o ADOT Communications
1655 West Jackson Street, MD 126F
Phoenix, AZ 85007

Toll-free Bilingual Telephone Hotline: 1.844.544.8049

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Arizona Department of Transportation

Alternatives Selection Report



Environmental Impact Statement





Fixing America’s Surface Transportation Act

Federal Highway Administration

Federal Railroad Administration






Interstate 11

Intermountain West Corridor Study




Maricopa Association of Governments

Moving Ahead for Progress in the 21st Century Act




National Environmental Policy Act

Nevada Department of Transportation



Pima Association of Governments




Record of Decision

Regional Transportation Commission of Southern Nevada



Safe, Accountable, Flexible, Efficient Transportation Equity Act: A Legacy for Users



Union Pacific Railroad