This document is the final environmental impact statement and final environmental impact report (FEIS/R) on the proposal by the National Railroad Passenger Corporation (Amtrak) to complete the electrification of the Northeast Corridor main line by extending electric traction from New Haven, CT, to Boston, MA. This FEIS/R supplements the draft document published in October 1993 and made available for public comment through January 21, 1994. Comments received on the Draft EIS/R have been reviewed and evaluated. In some cases design refinements were made, additional analyses were performed and further explanations of potential impacts were incorporated into the FEIS/R as a result of those comments. This FEIS/R presents a comprehensive assessment of the consequences of each project alternative on the natural, physical and social environment. Environmental consequences are identified and, where possible, quantified. Mitigation measures that will reduce or eliminate potential adverse impacts are also identified. The FEIS/R consists of four volumes. This document (Volume I) is the main body of the FEIS/R and includes a 4(f) Statement on the proposed location of an electrification facility in the Great Swamp Wildlife Management Area. Volume II presents additional technical studies to supplement Volume III of the DEIS/R issued in October 1993. Volume III of the FEIS/R presents summaries of comments received on the DEIS/R and responses to these comments. Volume IV reprints the comments received on the DEIS/R.