If you want to ride the MBTA for free, you could try the Davis Square Station on the Red Line. Fare gates there were wide open recently, examples of broken equipment and other inducements for fare evasion notoriously plaguing the T.

Now, they’re doing something about it.

In November, the MBTA struck a $723 million deal to outsource its entire fare collection system to Cubic Transportation Systems of San Diego. The company will install new fare gates that will open with the tap of a Charlie Card, credit card or smartphone — and will also work on buses and trolleys.

Cash will no longer be accepted aboard T vehicles. Instead, riders will be able to buy Charlie cards and add value to them — and to phones — at kiosks the T promises will be at every train station and a wide variety of neighborhood stores near bus stops, including bodegas.

While riders may welcome easier ways to pay, not everyone is convinced those are the best options.

“By and large, the people that use transit are middle-to lower-income. Donald Trump does not use transit,” said Richard Stewart, professor of transportation and logistics at the University of Wisconsin-Superior.

“When you say it’s tied to a phone, the question I have is what brand, what year? I may have a 6-year-old iPhone. Will that work?” asked Stewart, who says he’s happy with his older iPhone but found out its sim card didn’t work in some countries overseas, and his wife’s newer phone didn’t work in others. He also has concerns about credit cards, which may charge riders interest on a subway ride.

“Credit cards are a major issue for most low-income people,” he said. “For many of them, the way they budget is to use cash.”

Professor Richard Stewart of the University of Wisconsin-Superior shows off some of the fare cards he's collected from transit systems around the world, as well as older tokens. Stewart says there's no technical reason why the cards, some issued by Cubic, the company taking over the MBTA's fare collection, can't be made to be used inter-operationally on other transit systems Robin Washington for WGBH News

Stewart questions whether the T asked riders how they wanted to pay before moving ahead with this plan to ban cash on board. Agency officials say they did, pointing to a survey presented in September 2017 that said “the MBTA asked for customer suggestions on how to improve fare collection: 44 percent of the almost 800 comments will be addressed directly” by the new fare collection system.

Specifically, T officials say, a major reason for banning on-board cash payments is to effect more efficient operations overall. David Block-Schachter, the MBTA’s chief technology officer, says new fare validation machines installed at the back doors of buses and trolleys will allow riders to board through all doors instead of just the front by the driver.

“[We predict] up to a 10 percent improvement in speeds of our buses, because it so significantly reduces the time it takes to get on and off of buses,” he said.

Block-Schachter also defended the contract’s $723 million price tag. In November, he spoke before the MBTA’s Fiscal Control Board, explaining it “includes cash collection and servicing, it includes bank cards and processing fees, it includes streetscapes and vending machines, and new gates and turnstiles. We could go on and on.”

Most important, he said, is “we don’t pay them a dollar until the system is operational and working for our customers.”

Still, some riders remain skeptical.

Fare gates sit wide-open at the Davis Square Station on the Red Line in December, offering no hindrance to evaders. Courtesy Scott Moore

The T never lived up to promises made when it abandoned tokens for Charlie cards in its first try at automatic fare collection says Mela Miles, a longtime transit advocate and co-chair of the Fairmount Indigo Transit Coalition.

“You would see some big red strip that went across that said ‘Sorry, no cash accepted at this machine. Sorry.’ All of these sorrys. And it was really a sorry system that broke down a lot,” she said.

“I went to two train stations yesterday and they had gates wide open that said ‘Out of service.’ Now, they're wide open, but if you walk through, you have just become a fare evader," Miles continued.

Fare evasion remains a problem for Transport for London, which saw a slight rise in people riding buses for free after Cubic installed a similar system in that city. But overall, the London project has received praise. Retired MIT professor George Kocur worked on the algorithms for that project, and says they could be similarly used in Boston.

“There’s a feature in London called best value. You just tap away, and at the end of the week, you get the best fare as if you had done all the math yourself, figuring out whether you should get day passes or weekly passes, for which zones and which modes,” he said.

Kocur says the math also allows discounting of routes in low-income areas. T technology chief Block-Schachter says he’s excited about those possibilities, and so is transit activist Miles, so long as it works for everybody.

The way to determine that, says University of Wisconsin professor Richard Stewart, is for the T to re-evaluate the new system after it’s completely up and running, but before the contract runs out.

“Are they planning in year five ... to survey customers and say, ‘Is this better than what we had or worse?’ Or (maybe they will be) saying ‘Aren’t we smart!’ — this is so good!'" Stewart said. "That’s fine too, but you can’t wait until year 13 to do that.”

And, he says, whatever the result, it’s vital to weigh it against what riders had before.

“We had a system. It was called cash,” Stewart said. “Usable anywhere. Is legal tender for any and all debts. And now we’ve gone to a system where everything is different. I have to carry multiple things in my pocket to make this work, or I have to have multiple apps on my phone to make it work, when we had a universal system.”

Correction: An earlier version of this story misspelled Richard Stewart's name. This has been updated.