Can Mayor Wu really make the T free?

Drivers would be more likely to hop out of their carbon-spewing cars if public transportation was gratis, or so the argument went. And riders, many of them low-income people of color, would collectively save millions.

It was justice on wheels, a perfect shorthand for liberals who wanted to push Boston in a new direction — and for moderates who thought Wu was promising more than a mayor could deliver.

Here’s what it wasn’t: an idea that got a lot of scrutiny.

There was limited debate over the actual cost. Not a lot of discussion about how many people a zero-fare T could actually lure out of cars. And while there was broad talk of the political hurdles Wu would face — commentators pointed out that the mayor of Boston has no direct control over the state-run MBTA — there wasn’t much of an effort to game out potential paths to victory.

It is time, now, to game them out. To dive deep.

Wu isn’t just a candidate anymore. She’s the mayor. And she’s made it clear that freeing the T will be a central focus of her administration.

She’ll have to take a piecemeal approach. Covering the cost of fares systemwide — on buses, the subway, and commuter rail — would be an enormous expense. Before the pandemic, riders poured almost $700 million a year into fare boxes and ticket-vending machines, accounting for about a third of the MBTA’s $2 billion budget.

No one in the mayor’s office has any illusions about finding that kind of cash anytime soon — not in the city coffers; not in the state Legislature, which is the T’s primary benefactor; and not in Washington.

But Wu is determined to make a start. And she has focused on freeing the buses — which would be a far less expensive proposition than covering straphangers’ fares on the sprawling subway system.

So on her first full day in office, the mayor held a press conference in front of Ashmont Station in Dorchester and announced that the city would put $8 million in federal relief dollars into expanding a fare-free pilot begun by her predecessor, Kim Janey — growing it from one MBTA bus route serving low-income communities (the 28) to three (adding the 23 and 29) and covering the cost for a full two years.

The move, she said, will “reshape what’s possible in Boston.” And if she’s able to get the expanded pilot off the ground, and eventually find the money to make all the buses in the city free, it could reshape what’s possible elsewhere, too.

Wu’s push has already won substantial national attention — and success would bring much more.

But we don’t have to wait for the mayor’s slow build to get a sense of whether fare-free transit can work in Boston and other major American cities.

The deep history — and contentious present — of the idea can tell us plenty.

Melissa Baril sinks into a front-facing seat on the boxy blue Route 26 bus in downtown Worcester, her teenage son Caleb at her side.

She’s down on her luck these days. Out of work. Someone stole her car a few months back. And getting around is a challenge.

Baril has been taking occasional Lyfts, but they’re expensive. And she’s come to rely on Worcester Regional Transit Authority buses.

Today, she’s headed home after going to a doctor’s appointment, picking up some glasses for Caleb, and shopping for a few household items at Family Dollar.

When she first started riding the bus, she wasn’t sure what to expect. Would she have to buy a pass of some kind? Feed a couple of dollars into a fare box?

Neither, she was surprised to learn.

A local think tank, the Worcester Regional Research Bureau, planted the seed for fare-free transit with a 2019 report on the subject. And when the pandemic struck, the WRTA stopped collecting fares to spare drivers from interacting with passengers possibly infected with COVID.

The experiment has been extended several times. And thanks to the free buses, Baril has saved a little money here and there. It has helped. “Right now,” she says, glancing at the bruised floor of the bus, “I have a lot of things going on.”

Worcester is one of several cities nationwide that have experimented with fare-free public transit during the pandemic.

Los Angeles and Kansas City have made their buses free. Raleigh, N.C., and Richmond, Va., have done the same. And here in Massachusetts, the board of the Merrimack Valley Regional Transit Authority, which operates buses in Lawrence and surrounding towns, recently voted to expand a small pre-pandemic pilot — making all of its local routes free for at least two years starting March 1.

A free bus is, almost always, a more popular one.

In Worcester, the zero-fare policy — recently extended to the end of the year — has propped up pandemic-era ridership even as other areas have seen sharp drops.

By last fall, WRTA ridership was actually higher than it was before the pandemic, state data shows. And according to the agency, it stands at 95 percent of pre-pandemic levels now.

Zero fare has attracted an impressive roster of champions along the way — including transit advocates, state legislators, US Representative Jim McGovern of Worcester, and the Worcester Regional Chamber of Commerce.

But for all that success, the experiment is precarious.

The WRTA board is paying for the recently approved extension with federal relief funds. And Administrator Dennis J. Lipka says it’s hard to imagine fare-free service continuing when the money runs out. “I’ve had numerous calls from politicians and social services agencies — and the world — saying zero-fare is the way to go,” he says. “But no one has written a check.”

And the precariousness extends beyond Worcester.

The Lawrence pilot will be funded with one-time federal dollars, too. And the Los Angeles Metro is ending its experiment with free buses next week, citing financial concerns.

Money has long been a critical factor when it comes to zero-fare transit.

Nationwide, the few dozen transit systems that went fare-free before the pandemic were in college towns looking to shuttle students and staff around with minimal hassle, in resort towns hoping to reduce congestion during ski season, and in small cities and rural areas with limited ridership.

They are small agencies. And fares were a relatively small part of their budgets, making it less burdensome to forgo the revenue. Bigger systems that were more heavily dependent on fare revenue studied the idea but could never make the finances work.

It wasn’t just a matter of money, though.

Earlier fare-free pilots in larger cities like Denver and Trenton, N.J., had stumbled in a variety of ways. There were complaints — some of them overblown — about young people swamping the free buses, acting rowdy, and committing acts of vandalism. And the pilot projects failed to produce many of the hoped-for benefits.

One study of the Trenton experiment in the late ’70s showed that while making just some fares free accounted for a 15 percent jump in overall ridership, much of the gain was attributable to existing customers riding more. Often, they’d simply replace a long walk to the store with a free bus trip. And while that may have saved individual riders time, it did nothing to reduce gridlock or cut down on pollution.

Surveys showed the Trenton policy drew relatively few of the “choice riders” coveted by advocates — those who elect to get out of their cars and onto public transit. Indeed, the number of averted car trips was so small, the researchers wrote, that it “would never even be noticed, much less be considered statistically significant.”

The Trenton experiment happened decades ago, of course. But in Boston, where Janey started the fare-free pilot on the Route 28 bus and the Wu administration has extended it, some of the same trends are evident.

Ridership on the 28 is substantially higher than it is on other MBTA routes. But surveys show that 76 percent of riders would have taken the bus even if it weren’t free and 8 percent would have taken a different T service. Another 8 percent would have walked or biked, and just 5 percent would have used a car, driving themselves or taking a rideshare.

The automobile, it seems, still has a strong hold on Americans.

Baril, the Worcester mom, says she has appreciated riding the bus for free since her car was stolen. But when she gets her insurance settlement, she plans to buy a car and get off public transit. The bus has been better than expected, she says, but she sometimes waits 20 minutes or half an hour before one arrives.

For Baril, convenience trumps cost.

And the same seems to hold for regular riders of public transit.

In a 2015 survey for the T, bus riders ranked frequency, reliability, and speed among their top priorities. Fares, by contrast, were way down the list — just 8 percent said cost was a factor that “frequently” prevented them from using the MBTA.

National surveys have shown similar results. And for some transit advocates, that makes fare-free the wrong push.

“It is far more important to most riders to make transit better than to continue to have bad and mediocre transit that’s free,” says David Bragdon, executive director of TransitCenter in New York.

Eliminating fare revenue, he says, only makes it harder for agencies to deliver the level of service riders want. “Generally speaking, every dollar that is not collected in fares translates to a dollar’s worth of service cuts,” Bragdon says.

Fare-free transit becomes particularly difficult to justify, critics say, when you consider that it eliminates fares not just for poor bus riders but for the well off. Better to target any fare relief to those who need it most, they say, by offering reduced fares to low-income people, as cities like New York, Seattle, and Portland, Ore., have done.

The T has offered up that idea as its preferred alternative to fare-free transit. And advocates say they’re all for reduced fares as an interim step. But they have trouble believing it will get much traction when the T and the state Legislature have done so little to make the long-discussed proposal a reality.

Stacy Thompson, executive director of the LivableStreets Alliance, calls the lack of progress on reduced fares for low-income riders “the biggest frustration of my professional career.”

It’s time, she suggests, to reach for the bigger idea of zero-fare public transit.

Ari Ofsevit is a transit nerd.

King of spreadsheets. Master of the white paper.

His online biography calls him “a well known local transportation influencer.” And Thompson’s group, LivableStreets, named him Advocate of the Year not once but twice.

Ofsevit says he was skeptical of fare-free transit at first.

But after digging into the numbers, as he does, he’s concluded the idea not only has merit but is far more affordable than some might imagine.

His case rests, in part, on Boston’s unique transit history and geography.

In the early days of privately run transit, the Boston Elevated Railway was a leader in integrating different modes of travel. Hop off a streetcar, or later a bus, and you could step across a platform and get on the subway. Vestiges of that system still remain in places like Harvard Square.

That history combined with Boston’s layout — its narrow downtown streets put some limits on bus service in the heart of the city — has led to a transit system with a large number of people who ride buses to subway stations, transfer, and then take rail downtown. About 35 to 40 percent of bus trips include a transfer, according to the T.

Why does that make zero-fare buses more plausible?

Well, today a passenger who takes the bus and then transfers to the subway pays the equivalent of the standard $2.40 subway fare — $1.70 for the bus and then an additional 70-cent transfer fee to get on the train.

If all the local buses were free, many bus riders would still wind up hopping on the subway at some point on their trip and paying the full $2.40. And that means the T wouldn’t lose any revenue from those riders — making the cost of free buses lower than it might appear.

Taking that into account, Ofsevit did some back-of-the-envelope calculations using pre-pandemic figures and came up with an estimate of $30 million to $40 million per year — later refined to $33.7 million. That’s about 2 percent of the T’s annual pre-pandemic operating budget.

“The big question is, if you stopped collecting bus fares tomorrow, what would change?” Ofsevit says. “And I think the answer is, not that much.”

It’s an intriguing calculus. But there is a flip side.

If a large number of bus riders wind up paying full freight, that undercuts a prime rationale for going fare-free: saving low-income people money.

Ofsevit gets that. But if thousands of riders would still save millions of dollars per year, that’s a big win. And there are other benefits.

Since drivers wouldn’t have to wait for passengers to fumble through their wallets for passes or cash, Ofsevit says, the buses could move more quickly — improving service substantially.

Going fare-free could also help the T cut down on the cost of a long-delayed, nearly billion-dollar new fare collection system. After all, the agency wouldn’t need new vending machines along bus routes or card readers on the vehicles.

But though it all sounds good, color the MBTA skeptical.

In an analysis released in May, the agency pegged the cost of fare-free local buses at $97 million to $137 million the first year and $88 million to $122 million in subsequent years.

And if the T added extra buses and garage space to accommodate the expected bump in ridership, the agency says the cost would jump to $281 million to $623 million in the first year and $118 million to $188 million in subsequent years.

One important part of the T’s math involves The Ride, its door-to-door service for people who are disabled.

Federal regulations dictate that fares for this kind of service can be no more than twice as high as standard fares. And if you double zero, you get zero. That would wipe out existing fare revenue for The Ride. But just as important, the T says, it would boost demand for a service that is very expensive to operate.

Fare-free advocates say it’s crucial to accommodate riders who are disabled. But there is something perverse, they suggest, about a rule designed to help one vulnerable population getting in the way of an effort to help other vulnerable populations.

“We’re in a moment of urgency that has to be focused on finding solutions rather than staying focused on potential barriers,” Wu says. “Policies are up for policymakers to change and revise as meets the needs of the moment. And we have partners along city, state, and federal government who are ready to go all in on this.”

The mayor has already had some success, it seems, in clearing another legal hurdle.

On a recent trip to Washington, she asked US Transportation Secretary Pete Buttigieg to look into some federal regulations that appeared to pose a threat to her proposed two-year free-bus pilot.

And this week, the Federal Transit Administration told Commonwealth Magazine and the Globe that those regulations shouldn’t stand in the way.

It’s not just legal problems that fare-free advocates insist are overblown.

They also question elements of the T’s soaring estimate for the cost of fare-free transit — including its decision to factor in the cost of new buses and expanded bus yards to accommodate an expected jump in ridership.

They say that’s not fair when the MBTA has acknowledged it needs to provide more bus service whether it goes fare-free or not.

So, who’s closer to the actual cost?

“I think it’s somewhere in the middle,” says Brian Kane, executive director of the MBTA Advisory Board, which represents the cities and towns that contribute funding to the T. Advocates make a good point about bus-to-train transfers cutting down on the cost, he says, but the T knows more about its operations than any outsider.

Whatever the precise cost, tens or possibly hundreds of millions of dollars is a substantial amount of money. Where would it come from?

Getting Beacon Hill to pony up will be a challenge.

The state’s top political leaders made that clear right after Wu was elected in November.

“There’s no such thing as a free T,” said Republican Governor Charlie Baker, on WCVB’s “On the Record.” “There’s no such thing as a free lunch.”

State Representative Aaron Michlewitz, a North End Democrat who endorsed Wu for mayor and chairs the powerful House Ways and Means Committee, tells Ideas that he’s eager to see how the Boston bus pilots fare; an evaluation of the demonstration on the 28 bus route is expected next month.

But he suggests that Beacon Hill is more interested in improving the T’s existing service than launching new initiatives.

And “from a State House perspective, from the Commonwealth as a whole looking at this discussion,” he says, “I think our objective is, How do we provide equity throughout the entire [state]? Because I think there are still a lot of places that transit is not accessible.”

As Michlewitz’s comments imply, one of the biggest sticking points in the Legislature is that the T only serves a portion of the state — and lawmakers from outside Greater Boston have little interest in pouring huge sums into the agency.

Advocates are pushing for fare-free transit all over the state, and that may make the idea a bit more palatable. But the majority of the funding would still go to the MBTA.

There are some ways around that concern.

The state Senate, on several occasions, has passed legislation allowing for regional ballot initiatives. If the House signed off on the measure, with some tweaks, the communities served by the MBTA could vote to tax themselves — funding fare-free transit, improvements to T services, or both.

Local ballot initiatives to fund roads and public transit projects routinely pass by wide margins in other parts of the country; in 2020, local voters approved 90 percent of such measures, from Ogemaw County, Mich., to San Antonio to Seattle, according to the American Public Transportation Association, a nonprofit organization.

A big new tranche of outside cash could smooth over differences, too.

President Biden’s $2 trillion social spending and climate package, known as Build Back Better, is in trouble after Senator Joe Manchin of West Virginia said he couldn’t support the bill, depriving Democrats of a crucial vote in the evenly divided chamber.

But the legislation includes $9.75 billion to improve mobility for low-income people — including fare-free transit — and if Manchin can be brought back on board, Massachusetts could get an influx of federal dollars.

New state dollars are a possibility, too. In the fall, Massachusetts voters will cast ballots on a so-called “millionaires’ tax” that could raise as much as $2.2 billion per year for education and transportation initiatives. A lawyer for the group behind the measure tells Ideas that lawmakers could dedicate some of the funding to fare-free transit if they choose.

It’s possible, at least, that Beacon Hill will warm to the idea. Baker is forgoing a reelection bid, so the odds that a Democrat will win the corner office have improved substantially. Both of the major Democratic candidates for governor, Sonia Chang-Diaz and Danielle Allen, have voiced support for some version of fare-free public transit.

If the state doesn’t come through, Boston — or, more likely, a coalition of cities and towns in the region — could fund at least a partial freeing of the T themselves.

A loose network of municipal leaders is already forming around MBTA bus pilots. There is interest in Brookline. And the City of Cambridge is circulating a letter asking the state to standardize the process for establishing a pilot.

Fare-free transit “is definitely a priority for the Cambridge City Council,” Cambridge Mayor Sumbul Siddiqui tells Ideas.

A series of pilots would get the region partway there.

James Aloisi, a former secretary of transportation for the state of Massachusetts, says Wu could make further inroads by cajoling large employers to do what MIT already does across the river — subsidize public transit for its employees.

“If the Boston Globe, if Partners HealthCare, if Vertex, if Liberty Mutual — go on down the list of major employers in the city — all said . . . ‘We’re going to give our employees free transit,’ then the amount of public funding that’s going to be necessary to fill the gap just got a lot smaller, very quickly,” he says.

Wu tells Ideas she’s already started to talk to private employers about the prospect.

She’s also open to another possibility — buying MBTA passes in bulk and distributing them, the way the city already does for Boston Public Schools students. That approach would get around a significant legal hurdle: Since it would involve paying fares, rather than reducing them to zero, there would be no requirement to provide free door-to-door transit for disabled people in parallel.

This sort of piece-by-piece approach may, in the end, be the most realistic route to a freer mass transit system.

A partial liberation wouldn’t quite match the bold rhetoric of Wu’s mayoral campaign. But the rhetoric, in no small way, has served its purpose.

It has grabbed the public’s attention and it has stretched the bounds of conversation. We’ll see where that conversation takes us.

David Scharfenberg can be reached at david.scharfenberg@globe.com. Follow him @dscharfGlobe.