Marc Levy Added weekend hours means the MBTA will run until around 2 a.m. in the fall.

All subway lines and eight frequent bus routes will get an extra hour of late-night rides Fridays and Saturdays starting Aug. 24 as part of fall service changes, and five bus routes – those with the most late riders – will get extended service every day of the week, the MBTA said Tuesday.

To encourage riders to take advantage of the extended service, all subway, buses, ferries, commuter rail and Ride trips – which serve seniors and people with disabilities – will be free Fridays and Saturdays from 9 p.m. to the end of service in September and Oct. 3–4, Massachusetts Bay Transportation Authority officials said.

Frequency during the hour of extended T service will be about every 30 minutes on the Ashmo

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