For the first five weekends after the change, commuters can ride for free on any train, ferry, or bus line. The MBTA says most buses and trains will run every 30 minutes during the extended hours. On the Red line, between Alewife and JFK/UMass, trains will run every 15 minutes.

To introduce the new hours, the MBTA will offer fare-free service on five Friday and Saturdays nights after 9 p.m., starting Sept. 5.

The MBTA will soon be adding late-night weekend service to subway lines, as well as popular bus routes in the Boston area.