the Providence/Stoughton Line has 36. Running times vary from 30 minutes on the Fairmount Line to nearly 120 minutes for some Providence/Stoughton Line trips, with 60–75 minutes typical. Most trains stop at all stations on the line; some peak-hour express trains operate on the Framingham/Worcester and Providence/Stoughton lines. Several lines additionally have some short turn service. The CapeFlyer, a seasonal weekend-only service to Cape Cod, operates using MBTA equipment over the Middleborough/Lakeville Line plus the Cape Main Line (which is not otherwise used by the MBTA). Special express service to Foxboro station is operated during New England Patriots home games and some other events at Gillette Stadium. It runs from South Station via the Franklin Line, and from Providence via the Providence/Stoughton Line. During the winter, one "ski train" round trip of the Fitchburg Line operates with a bicycle car on weekends and Wednesday evenings, with a shuttle bus to Wachusett Mountain. All MBTA commuter rail service is provided by push-pull trains powered by diesel locomotives (see ). Maximum speed for trains is , though some lines have lower limits. The entire system is signalled and operates with Positive Train Control using the Advanced Civil Speed Enforcement System. The southside lines have cab signals for automatic train control; cab signals will be placed in service on the northside lines in 2023. The MBTA is a member of the Northeast Operating Rules Advisory Committee (NORAC) and uses its operating rules. Most portions of the system operate under NORAC rules 261 and 562, which allow bidirectional train movements on every track (such as an express train passing a local train in the same direction). Portions of the Fitchburg, Haverhill, and Newburyport/Rockport lines operate under NORAC rule 251, which allow trains to run only in a single direction on each track. Most lines are either double track, or single track with passing sidings; portions of the Northeast Corridor have three or four tracks. Freight service Freight service is operated over most of the MBTA Commuter Rail system by several private railroads. CSX Transportation operates freight on most southside lines, of which the outer portion of the Worcester Line has the most freight traffic. Massachusetts Coastal Railroad operates south of Middleborough on the Middleborough/Lakeville Line, as well as on future South Coast Rail trackage. The Fore River Railroad operates between Braintree Yard and East Braintree on the Old Colony mainline and the Greenbush Line.