The idea has been bandied about in small circles of transportation advocates for years. But it has gained much wider discussion since since last year’s MBTA fare hike . In the face of protests from activists and politicians, T officials elected not to increase bus fares, and one of the most prominent proponents of free fares, Boston City Councilor Michelle Wu, is widely seen as a potential candidate for mayor .

Against this backdrop, a once-radical idea to fight Boston’s horrific traffic has seemingly taken hold: Eliminate transit fares outright, or at least make rides on Massachusetts Bay Transportation Authority buses free.

It promises to be a big year on the transportation front, as the Legislature prepares to debate new money for the rail and road systems that may prove at odds with funding initiatives already backed by Governor Charlie Baker.

So far, it’s been easier to put free fares to a real-world test in smaller transit systems. Lawrence has seen a 20 percent bump in ridership since agreeing to pay fares on three routes, while in Kansas City, Mo., officials are about to make all city buses free.


“What if you could just get on a free bus, and then, with less traffic congestion, the air was being cleaned up?” said Pamela Miles of the T Riders Union. “I really believe it would be win-win, and it’s starting to gain traction around the country.”

The proposal has run into resistance from state officials. Pointing to their decision not to raise bus fares, they prefer the MBTA to stagger prices — by, for example, establishing fare discounts for low-income riders.

Skepticism also extends to some pro-transit organizations that question whether larger agencies could handle losing fare revenue while facing budget pressures and demands for better service.


“Are you actually making transportation more affordable if a lot of bus service remains very infrequent and doesn’t reach the places it needs to reach for people to have access?” said Ben Fried, spokesman for the New York-based nonprofit TransitCenter, which organizes transit advocacy nationwide. “The price of the fare matters to riders, but they prioritize frequency of service.”

Nowhere in the world has a transit agency the size of the MBTA ditched fares, Fried said. Even eliminating fares only on T buses would be “incredibly ambitious,” he added. Going fare-free in Kansas City will cost about $8 million — far less than it would cost the T to make buses free.

To some observers, however, eliminating fares seems more equitable than other ideas to address Greater Boston’s traffic crisis and the pollution it entails, like making driving more expensive.

“A lot of the policies on the table, like fees to disincentivize driving, have environmental benefits, but hit low-income and moderate-income people the hardest,” said Phineas Baxandall, an analyst with the left-leaning Massachusetts Budget and Policy Center. “Free fares advance both equity and the environment.”

The push in Boston took off last year when Wu called for the T to move to free fares systemwide, but starting with select bus routes, ahead of the agency’s rate hike on July 1 — its fourth since 2012. It has gained support as the MBTA prepares to install a new fare-collection system for buses and trains that could cost nearly $1 billion.


Advocates say eliminating bus fares would accomplish one of the primary goals of the new fare system, which promises to speed service by eliminating cash payments onboard and allowing riders to enter through both front and back doors.

“To me, this is not a giveaway,” said Stacy Thompson of the Livable Streets Alliance, which advocates for better transit options. “This is really about how do you make the bus system more efficient and more desirable with the resources we have today.”

Cost, as always, is front and center. The T collects about $700 million in fares a year, funding roughly one-third of its operating budget. While buses account for a fraction of that, fare-free skeptics say the agency cannot afford to forgo money amid several expensive initiatives — from systemwide repairs to modernizing the commuter rail.

“The T needs additional operating revenue to maintain its current levels of service,” said Brian Kane, deputy director of the MBTA Advisory Board, which represents cities and towns with T service. “Anything that will have to be paid for with additional money is just going to make that more difficult.”

Supporters, however, argue that eliminating fares on local MBTA bus routes could be done on the relative cheap: maybe as little as $36 million a year, according to an estimate by the Livable Streets Alliance. That number, which does not include the Silver Line or long-distance express routes, reflects the fact that a huge portion of MBTA bus riders transfer to the subway, paying $2.40 for a combined trip, or hold a monthly bus-subway pass, and would continue to pay for the train service even with free buses. Making most buses free on the T and every other public bus system in the state could be covered with a 2-cent gas tax increase, according to Livable Streets.


State officials question those numbers, because some subway riders may choose to travel solely by bus, costing the T those fares. And federal rules may also require the T to make its door-to-door service for people with disabilities less expensive, further adding to the deficit, as would costs associated with running more buses to address additional demand.

“It’s a more complicated conversation than people have made it out to be,” said Transportation Secretary Stephanie Pollack. “I’d like to provide a bus service that’s good enough that people are willing to pay for it, rather than concede that service is terrible and we should offer it for free.”

Pollack said the state would listen to offers from outside parties to lower fares, but added that service may suffer if the T covered the costs itself.

Fare-free proponents acknowledge the estimate may be low because of these factors, but said it offers a preliminary cost.

A further complication is a state law that suggests, though does not mandate, that transit agencies over time increase the portion of their budget funded by fares.


The Boston Globe Editorial Board, which recently endorsed fare-free buses, said employers or philanthropists could pay for service on select routes. Another option could be tapping municipalities for funds, as Lawrence is doing.

In Boston, officials are more focused on paying for student passes and working with the T to improve bus service and aren’t likely to underwrite free buses anytime soon, said Chris Osgood, Boston’s chief of streets.

Supporters and skeptics agree on one thing: fare-free buses would require big service upgrades to address new ridership and potential crowding.

Officials are already preparing to expand bus service, including buying 60 new vehicles, but will have other big costs associated with further expansion like building or expanding garages to house buses. The MBTA also continues to push for more bus-only lanes on local roads.

Wu, the Boston councilor, said there’s a reason her push to eliminate fares has caught hold.

“Commutes are getting longer, traffic is getting worse, the struggle to get to work on time is intensifying, no matter the mode,” she said. “So we’re at the point now where people are ready to talk about bold solutions.”

Adam Vaccaro can be reached at adam.vaccaro@globe.com.