What is a Tier 1 EIS?
A Tier 1 EIS is an environmental document that identifies what the existing conditions of the study area are and evaluates potential effects of the proposed project on those conditions. A Tier 1 EIS addresses broad, overall corridor issues such as general location, mode choice and land use impacts. This approach allows project sponsors to make corridor-level decisions without incurring the time and expense of design that would be required in a more detailed EIS.
