BOSTON MAYOR Michelle Wu is extending her free bus initiative for another two years, agreeing to use $8.4 million in federal funds to make sure three MBTA bus routes in the city remain fare free until March 2026.

Wu earlier had signaled her intention to extend the fare-free arrangement with the MBTA, but until Tuesday her administration had refused to provide any details. Her move to extend the free bus routes comes as Gov. Maura Healey and the MBTA are preparing to launch a half-priced fare on all T services for qualifying low-income riders.

The mayor, who has said in the past she would like to make the entire T free and would especially like buses to be free, launched the fare free bus initiative early in her administration and then extended it for two years. The two-year experiment, which was scheduled to stop at the end of February, is now being extended another two years.

The latest extension, like the earlier incarnations, uses American Rescue Plan Act funds to reimburse the T for lost fare revenue. The cost between the first two-year experiment and the current one is increasing by $400,000 to $8.4 million.

The three free buses are the 23, 28, and 29 routes, which run through parts of Dorchester, Mattapan, and Roxbury. City officials say half of the riders on the routes are low income and ridership overall is high. The officials said Route 28 ridership is at 102 percent of pre-COVID levels, while the Route 23 is at 94 percent and the Route 29 is at 64 percent.

One of the big advantages of the fare free bus experiment is that riders can board at both doors and dispense with paying fares, which can be time consuming. In the city’s press release, officials said dwell times (the time spent at stops) have fallen on the Route 23 and 28 buses, but indicated they have not declined on the Route 29 bus.

Wu’s decision to extend the fare free bus initiative suggests she is not giving up on her pursuit of free service even as Healey pursues a half-priced fare on all T services for anyone making less than 200 percent of the federal poverty level. Under Healey’s proposed low-income fare, qualifying bus riders would pay 85 cents for a bus ride, half the regular fare of $1.70.

Wu’s representative on the MBTA board pushed back against the low-income fare in December, asking T staffers to research whether it would be more cost-effective to just eliminate fares entirely rather than continuing to spend money on equipment to collect reduced fares. But at the January board meeting the city’s representative moderated her concerns and no longer demanded cost comparisons.

By extending her free bus initiative another two years, Wu seems to believe that free bus could work in conjunction with the low-priced fare favored by the governor. City officials say 50 percent of the riders on the three bus routes saved money (an average of $35 a month) while the other 50 percent saved nothing because they used monthly passes or transferred to the subway or commuter rail system where they had to pay to ride. With the low-income fare, the fares on the subway and commuter rail would be cut in half.

Brian Kane, executive director of the MBTA Advisory Board, said Wu is clearly not giving up on free bus fares. “The mayor believes in this and her staff believes in it and they’re putting the city’s money behind her campaign pledge,” he said.

Kane also said the data seem to indicate fare free buses and a low-income fare could work well together. “The low-income fare and the free bus could work really well in tandem with each other,” he said.

In the city’s press release, a quote from MBTA General Manager Phillip Eng indicated the city and the MBTA are working together. “We have a common goal in making mass transit more affordable,” he said. “Our combined efforts, from Boston’s fare-free bus program to Gov. Healey’s proposed low income fare program, are benefiting communities who take all different modes of transit – buses, subways, commuter rail, ferries, or paratransit. We are improving people’s quality of life and making a real difference, building a more equitable and affordable transportation system network for all who depend on it.”

The big question mark is where the money to eliminate bus fares long-term would come from. Healey in her state budget for the coming fiscal year included $45 million for her low-income fare initiative. Neither the governor nor the T has shown much interest in eliminating fares entirely. At some point, the city is going to run out of federal funds it can spare to eliminate fares.

Bruce Mohl oversees the production of content and edits reports, along with carrying out his own reporting with a particular focus on transportation, energy, and climate issues. He previously worked...