Bus fares on three MBTA routes servicing riders in Dorchester, Mattapan and Roxbury will be eliminated for two years starting March 1 under a pilot program Boston Mayor Michelle Wu said Wednesday had been finalized using $8 million in federal COVID-19 relief money.

Wu made the announcement from Blue Hill Avenue in Dorchester on Wednesday morning, bringing to completion an initiative she launched on her first day in office back in November.

The two-year pilot program being run in conjunction with the MBTA will make service on the 23, 28 and 29 bus lines free until at least early 2024, building on the fare-free pilot acting Mayor Kim Janey launched in August on the 28 bus route.

Wu first raised the idea of eliminating fares across the MBTA system almost four years ago as a city councilor, and free public transit was a major platform of her campaign for mayor last year. When asked about that goal, Wu described this pilot as a first step.

"Do I hope that this leads to an entirely free MBTA? Absolutely. We've been talking about that for a long, long time," Wu said. "You know, we know that transportation, and public transit in particular, is the foundation of so much. It's life-changing when we can remove that barrier for people."

Ultimately, Wu said transportation is about “connectedness … connecting us to health care, to education to jobs and to each other.”

Though the City Council approved Wu's request to use $8 million from the city's share of American Rescue Plan Act funds for the fare-free bus pilot in December, Wu said finalizing the project required cooperation between city, state and federal partners as City Hall worked to overcome questions raised about whether the pilot could run longer than six months under Federal Transit Administration regulations and whether it would satisfy equity rules if the fares were to revert in two years.

Boston Chief of Streets Jascha Franklin-Hodge said that in the six months since fares were eliminated on the 28 route boarding times have been reduced by 20 percent and ridership has surged to 90 percent of pre-pandemic levels, making it the most popular route in the system with almost 12,000 riders a day.

Both Wu and MBTA General Steve Poftak acknowledged that finding a long-term funding source to replace lost fare revenue will be necessary if rides are to remain free after two years or if the fare-free bus concept is to be expanded.

"I think there's some important questions about funding that would need to be answered," Poftak said.

GBH News reporter Bob Seay contributed to this report.