The MBTA reported a boost in post-Labor Day ridership, bringing levels to among their highest rates since March 2020, when widespread pandemic shutdowns began.

The bump was driven by students and office workers returning to classes and in-person work this fall, and more frequent use of the commuter rail and buses during the Orange Line shutdown.

“We are seeing higher ridership during peak periods than any time since pre-pandemic, but these numbers are still well below pre-pandemic levels,” states a Friday memo from the MassDOT/MBTA Office of Performance Management and Innovation.

Subway ridership is at 51% of pre-pandemic levels. The highest numbers were seen on the Blue Line, at 64%. The Orange Line, which was closed for 30 days from Aug. 19 to Sept. 18, had the lowest reported ridership, at 46%.

“Excluding the Orange Line for more accurate comparisons, we saw roughly 65,000 taps per weekday during the traditional a.m. and p.m. peak periods over the last three weeks,” the memo said, adding it was the highest peak ridership since March 2020.

However, the memo to MBTA General Manager Steve Poftak outlines how displaced Orange Line riders boosted ridership levels on the commuter rail and buses, with increases continuing after the shutdown ended.

Some bus routes are at 90% of pre-pandemic levels, including two routes that are part of the fare-free bus pilot in Boston, 23 and 28, and others where service has been added since 2019, such as 16, 116/117 and Silver Line 3.

“Bus ridership has been consistent and relatively strong throughout the pandemic, but reached pandemic-era highs in September 2022 with the addition of displaced Orange Line riders,” the memo said.

“Even after the closure, bus ridership systemwide has been between 70-73% of the comparable week in 2019.”

Commuter rail ridership also increased significantly in September, and now averages about 70% of pre-pandemic weekday levels.

During the shutdown, fares in Zone 1, 1A and 2 on the commuter rail were free to encourage use of the alternative service. The Fairmount Line, which includes Zone 1A and 2 stops, is at 100% of pre-pandemic levels.

The Worcester, Franklin, Kingston/Plymouth and Greenbush lines all reached new pandemic-era highs in September and maintained high ridership this month.

“The largest changes were seen on the commuter rail system and persisted after the Orange Line returned to full service,” the memo said.