A corridor study is a planning-level assessment occurring before project-level activities and environmental compliance under the National and Montana Environmental Policy Acts (NEPA/MEPA). This process provides a link between early transportation planning and environmental compliance efforts and involves a planning–level evaluation of safety, operational, and environmental conditions to identify needs and constraints.
MDT can save time and money in subsequent project phases by facilitating early identification of constraints through coordination with local governments, resource agencies, and other stakeholders; screening of possible improvement options; and elimination of infeasible options.
A corridor study considers multiple improvement options to address the needs and objectives within a defined study area. The planning process is distinct from a NEPA/MEPA environmental compliance document and from design, right-of-way acquisition, and construction phases for an individual project.
For additional information, please see MDT's planning study process.
The National and Montana Environmental Policy Acts (NEPA/MEPA) require state and federal agencies to disclose impacts resulting from state and federal actions. In the context of transportation projects, the NEPA/MEPA process is intended to assist officials in making transportation decisions, while considering the human and natural environment and the need for a safe and efficient transportation network. The NEPA/MEPA process ensures that information about anticipated transportation project impacts is available to the public before decisions are made and implemented.
A corridor study is a pre-NEPA/MEPA effort that involves a planning-level assessment of the study area. The planning process includes a review of potential environmental issues and concerns. The results of this planning-level environmental review could be used to assist in later NEPA/MEPA environmental compliance phases for an individual project.
The Montana Department of Transportation (MDT) is conducting this study in collaboration with the Federal Highway Administration (FHWA), Broadwater County, Gallatin County, local communities within the study corridor, resource agencies, and the public. Robert Peccia and Associates (RPA) is assisting MDT in completing the planning effort.
Members of the public are encouraged to participate in the planning process. Multiple rounds of outreach will be held during the corridor study process. MDT will offer in-person meetings at several locations within the study corridor as well as virtual meetings and online engagement opportunities.
Public comments will be collected and considered throughout the planning process. To submit a comment, please contact one of the study contacts or submit a comment. A formal public review and commenting period will be held after the draft I-90 Corridor Study is completed.
The corridor study will identify and evaluate potential improvement options for the study corridor. This early planning process is distinct from future environmental compliance, design, and construction phases of an individual project. MDT may advance identified improvements into future design and construction phases as funding allows. Any future steps will be determined by MDT in conjunction with FHWA, Broadwater County, Gallatin County, and local communities within the study corridor.