Section 216(a) of the Federal Power Act, as amended by the Energy Policy Act of 2005, directs the U.S. Department of Energy (DOE) to conduct a study every three years on electric transmission congestion and constraints within the Eastern and Western Interconnections. Based on these studies, and comments concerning them from states and other stakeholders, the Secretary of Energy may designate any geographic area experiencing electric transmission capacity constraints or congestion as a national interest electric transmission corridor (National Corridor). Based on the 2006 study, two National Interest Electric Transmission Corridors were designated in 2007. These were invalidated by a federal appeals court in 2011.

The 2006 study was the first Congestion Study that the Department conducted. A second Congestion Study was conducted in 2009. A third Congestion Study was released in September 2015. 


Background Documents - 2006 Congestion Study

The Federal Register Notice of Inquiry requesting comments and providing notice of a technical conference was issued on February 2, 2006.

A public technical conference on the 2006 study and criteria for designation of National Interest Electric Transmission Corridors was held on March 29, 2006.

The Department of Energy issued the 2006 National Electric Transmission Congestion Study in August 2006.

* In the Bipartisan Infrastructure Law of 2021, Congress expanded the scope of the National Transmission Congestion Study, now called the National Transmission Needs Study (Needs Study), to include both historic and anticipated future capacity constraints and transmission congestion to more accurately identify high-priority national transmission needs.