In order to comply with the requirements of the National Environmental Policy Act (NEPA), the Illinois Department of Transportation (IDOT), in conjunction with the Federal Railroad Administration (FRA), has conducted a significant analysis of the potential impacts of the Chicago to St. Louis Corridor work on the natural and built environment.
An environmental impact statement (EIS) is a process established under NEPA and is required for federal projects that might significantly impact the human environment. Due to the complexity and length of the proposed project corridor (284 miles), a tiered EIS process was used.
To account for the complexity of this project, the NEPA analysis is divided into two tiers. The Tier One analysis consisted of a high project-level review and involved the selection of a Preferred Alternative. The results of the Tier One analysis thereby set the stage for more in-depth discussions and analysis in Tier Two, which will include more detailed engineering and environmental studies for the Preferred Alternative.
The Tier One analysis was completed with the FRA’s issuance of the Record of Decision (ROD) in December of 2012; the Tier Two Study for the Springfield Corridor Alternatives portion of the route was conducted concurrently with the Tier 1 study. The Tier 2 process for the Chicago to Joliet segment, the Granite City to St. Louis segment, and the Springfield flyover began in Fall 2013.