The 2006 National Congestion Electric Transmission Study, required by section 216(a) of the Federal Power Act, examines transmission congestion constraints and identifies areas that are transmission-constrained. This is the first Congestion Study the Department conducted. 

Based on this study, two National Interest Electric Transmission Corridors were designated in 2007. They were invalidated by a federal appeals court in 2011. 

Comments and form letters were submitted by the public in response to this study.