MP 1 (Back Bay Station) to MP 92 (Wilbraham). MP 3 to MP 44 has been transferred to the MBTA (Keolis Commuter Rail) and is referred to as the Worcester Main Line between those mileposts. The former Fitchburg Subdivision has been removed and is considered a running track between QBU 4.3 TO QBU 34.9 (Fitchburg) to QBU 34.9 (Framingham) and under control of the Fitchburg Yardmaster on channel 64
