Positive Train Control is scheduled to be implemented on the entire system per a federal mandate, which requires installation by the end of 2018 with the possibility of a two-year extension. , the MBTA expects to complete PTC on the southside lines by December 2018, on the northside lines by March 2020, and an overlay for freight on the sections of Pan Am Railways' Freight Main Line which overlap MBTA territory by August 2020. In August 2020, the MBTA reported the system was deployed and undergoing a calibration phase until full operation begins in December 2020 (in time to meet the twice-extended federal deadline).