NEPA Process

The National Environmental Policy Act of 1969 (NEPA) requires environmental documentation to secure federal clearance and funding for transportation improvements. There are different levels of environmental documentation required depending on the level of impacts a project may have. An Environmental Impact Statement (EIS), the highest level of environmental documentation required, evaluates whether proposed improvements will have any impacts on the natural, social or man-made environment.

A Supplemental Environmental Impact Statement (SEIS) reviews the findings of an existing EIS. A SEIS considers new or additional environmental impacts based on the introduction of new improvement options and/or major changes in the natural environment or communities.

The South Lawrence Trafficway SEIS evaluated if – and how – upgrading the corridor to a four-lane freeway, modifying access, and exploring new funding mechanisms would alter the impacts and recommendations previously identified through the 1990 EIS and 2008 East Leg EIS. The SEIS process exists to ensure proper identification and minimization of impacts to sensitive environmental features within the project study area. The SEIS was completed in early 2022.