Amtrak is substituting a bus for the Boston section of the Lake Shore Limited on Aug. 21-24 due to CSX track work.
Buses also are replacing the Boston section this week through Wednesday.
Passengers bound for Pittsfield, Springfield, Worcester, Framingham and Boston (South Station) will board a bus at the Albany-Rensselaer station to continue their journey or board at their intermediate station if originating east of Albany.
The bus will not stop at Boston Back Bay station.
Westbound passengers will also board a bus at their boarding station except at Boston Back Bay, which is not being served during the time when Nos. 448 and 449 are not operating.
Back Bay passengers are advised to contact MBTA for travel information to or from that station.
Passengers boarding at Boston South Station should go to the Amtrak Information Desk for instructions on boarding the buses.
Those boarding at Framingham will board their bus at the drop-off/pick-up area for the Track 2 platform (at Waverly Street).
Worcester passengers should go downstairs to the intercity bus area and board the bus marked Premier Bus.