THE SUMNER TUNNEL shutdown on July 5 prompted an increase in MBTA passenger levels on subways, buses, ferries, and commuter rail, but the increase wasn’t as big as expected and there’s little evidence that people who tried public transit during the closure remained riders after the reopening on August 31.

According to a presentation to the MBTA board of directors on Tuesday, the big takeaways were that free fares on the Blue Line didn’t boost traffic significantly, that the Orange Line performed surprisingly well, and that more people were riding public transit on the weekends than weekdays.

“People are fickle and getting them to change is hard,” said Lynsey Heffernan,  assistant general manager for policy and transit planning. “Folks who are in cars are hard to get out of cars.”

According to MBTA estimates, 40,000 cars travel through the Sumner Tunnel on a typical weekday. Once the tunnel was shut down, the T estimates three-quarters of the cars just traveled a different route  – 10,200 used the Ted Williams Tunnel, 10,400 used the Tobin Bridge, and 10,000 used other roads.

The MBTA estimates the riders of 3,900 cars, or nearly 10 percent of the total, shifted to public transit, while 5,500 cars just stopped coming in because their owners were either working remotely or on vacation.

The T estimates trips on the Blue Line increased 7 percent on weekdays during the shutdown, despite the absence of fares. Trips increased 4 percent on the Orange Line, 17 percent on the commuter rail, 3 percent on bus, 2 percent on the Silver Line, and 72 percent on ferries. All of the percentages were based on T estimates of what traffic would normally be at that time.

Surprisingly, weekend ridership was better. Trips on the Blue Line were up 13 percent, 23 percent on the Orange Line, and 41 percent on commuter rail. “We saw really strong growth on weekends,” said Martha Koch, a senior policy analyst at the MBTA.

The biggest disappointment is that most riders who tried public transit during the tunnel shutdown did not continue riding after the tunnel opened. Weekday ridership dropped 3 percent on the Blue Line and 58 percent on ferries after the reopening. By contrast, Orange Line ridership weekdays was up 14 percent and commuter rail posted a 1 percent gain.

Weekend ridership after the reopening was down across the board, except on the Orange Line, which posted a 1 percent gain.

The T made every effort to make its service more attractive during the shutdown, eliminating fares on the Blue Line, adding trains on the Blue and Orange lines, and setting headways between trains on the Blue Line at six minutes. Customer surveys indicated those riders satisfied with Blue Line service increased from 36 percent to 53 percent.

The subway also had major advantages over driving during the tunnel closure. The T compared travel from East Boston to downtown by car and by Blue Line during the week before the tunnel reopened and the Blue Line was twice as fast – a 14 minute trip by train versus 28 minutes by car.

Still, riders did not flock in great numbers to the Blue Line during the tunnel closure and did not continue riding after the tunnel opened.

“Fare mitigation was appreciated, but did not induce the ridership expected,” said Heffernan.

Thomas McGee, a member of the MBTA board from Lynn, thought T staff was overly pessimistic about the numbers.  He said the ferry between Lynn and downtown did very well and the fare reduction on the Newburyport-Rockport line attracted a lot more riders.