Study-Based Rating Methodology update
ATC implemented Study-Based Ratings Methodology (SBRM) on June 1, 2013 to better manage operational risk of conductor damage and clearance problems. ATC will use transitional ratings to mitigate reliability and minimize congestion issues created by the SBRM ratings until a project or another form of mitigation can be completed. The list of transitional ratings and mitigation projects is subject to change based on further analysis.
For the lists of facilities affected by SBRM and transitional ratings, see tables on the ATC OASIS page: