Fairmount commuter rail line will be free while Red Line’s Ashmont branch and Mattapan line are closed, officials say

The Fairmount commuter rail line at the Blue Hill Avenue stop in Mattapan.Jonathan Wiggs/Globe Staff

The Fairmount commuter rail line will be free from Oct. 14 to Oct. 29 while the Red Line’s Ashmont branch and Mattapan line are closed for “major track improvements,” officials said.

Shuttle buses will replace trains during the 16-day closure, the MBTA said Wednesday. But if riders choose the Fairmount line instead, they can ride for free, officials said.

“The upcoming work on the Ashmont Branch and Mattapan Line is critical to addressing and improving safety and reliability along this stretch of the Red Line, and the complete closure of these lines allows us to accomplish vital work in 16 days,” said MBTA general manager Phillip Eng. “By offering alternative shuttle bus service and now announcing free travel on the Fairmount Commuter Rail Line during the closure, we want our riders to know that we want them to continue to use mass transportation while we perform this work.”