The Fitchburg Line is a branch of the MBTA Commuter Rail system which runs from Boston's North Station to Wachusett station in Fitchburg, Massachusetts. The line is along the tracks of the former Fitchburg Railroad, which was built across northern Massachusetts, United States, in the 1840s. It is one of the MBTA's more scenic commuter rail lines, passing by Walden Pond between Lincoln and Concord. Weekend service includes a specially equipped seasonal "ski train" to Wachusett Mountain during the winter.
At 54 miles (87 km) long, the Fitchburg Line is the second-longest line in the system (and was the longest until the Providence/Stoughton Line's 2010 extension to T. F. Green Airport and later to Wickford Junction), and ranks as one of the worst lines in terms of on-time performance. The Fitchburg Line has the oldest infrastructure in the system, and commuter trains must share trackage with freight trains on the outer segment of the line. Only ten of the line's nineteen stations, including both terminals, are fully handicapped accessible - the lowest proportion of any MBTA Commuter Rail line.
Despite poor performance, the Fitchburg Line still draws about 10,000 daily riders, which is expected to increase after the 2016 completion of a massive improvements project. The $150 million project included adding nine miles of double track, an extension to Wachusett, rebuilding two stations, and building a new layover yard.
The Fitchburg Railroad opened between 1840 and 1845 from Boston to Fitchburg. The Boston and Maine Railroad leased the Fitchburg Railroad in 1900 and bought it finally in 1919.