Home > Regulatory Requirements > ATC & TTC ATC & TTC Information on this complies with FERC requirements to post information about Available Transmission Capacity, Transmission Reliability Margin, and Total Transfer Capacity. Attachment A Methodology Available Transmission Capacity (ATC) Transmission Reliability Margin (TRM) Capacity Benefit Margin (CBM) TTC/ATC/CBM Values ATC & TTC Algorithms