As Massachusetts prepares for the second phase of reopening, there is still concern across the region about how those who rely on public transportation will be able to safely and efficiently get to work amid the coronavirus pandemic.

For many, the answer is to use their bike, walk or take their cars. But for many in communities like Chelsea, East Boston and Revere, where many of the essential service workers live, the T’s buses and subways are the only way to get to work. And, as more people return to their jobs, those routes are expected to get more crowded.

The MBTA is currently running about 60 percent of its normal schedule of buses and subways, and officials plan on increasing service during Phase 2 of the opening, which is expected to begin on Monday. By Phase 3, which will start no earlier than June 29, the MBTA is expected to restore full service. As more people return to work and ridership increases, the T says it will add more buses and subways to corridors where crowding is observed.

General Manager Stephen Poftak is expected to provide more details Monday, but there is no doubt this is one of the biggest challenges the T has ever faced: how to provide the public transit service that people need in a way that makes them feel safe in the era of COVID-19.

While the T has increased service on some bus routes during the first weeks of the pandemic, many riders have said they don’t feel comfortable on public transportation. In May, a WGBH News/Boston Globe poll found only 18 percent of respondents would feel comfortable riding buses, subways, or commuter trains once we are allowed to again.

As a member of the T Riders Union, Mela Miles of Roxbury says she hasn’t taken the T since the pandemic shutdown began. “I do not feel safe at all. I didn't feel like they would thoroughly clean the bus because they never did it before,” she said, noting that she sees crowded buses and trains with passengers wearing improvised, inadequate face coverings, or none at all. “People forget that they have to stay 6 feet away from you, and you can't really keep a safe distance on the back of a bus.”

”There was overcrowding throughout the crisis, and we've seen that now being even more as more folks are going back to work,” Maria Belen Power, assistant executive director of Green Roots, an environmental and health organization based in Chelsea, told WGBH news. Power expressed concerns that the shuttle buses deployed during the recent Blue Line rehab work, which were supposed to be frequent enough to avoid crowding, didn't work.

The MBTA has set occupancy limits that would allow people to maintain physical distance from each other on T vehicles. In general, safe occupancy will mean less than half the usual number of riders on buses, subways and trains. On a typical bus, that will be 20 passengers instead of 58. On a Red Line car, 57 people will be considered max occupancy instead of 142.

How the T will manage maintaining that limit remains unclear, but in addition to operating as many buses and trains as possible, T officials are exploring ways to communicate with riders in real time how crowded a vehicle is either on the on the vehicle itself or through the T-Alert smartphone app. To alleviate crowding by the backdoors of buses, the T will once again allow for passengers to board through the front door.

Jarred Johnson, the chief operating officer of TransitMatters, an organization dedicated to improving public transportation in Boston, praised the MBTA for its responsiveness to rider concerns thus far.

“They've been responding to people's complaints about the buses being too crowded and are adjusting frequencies and adjusting headways in real time and that's been great and the T needs to keep doing that," he said.

As more riders return to buses and subways, enforcement of regulations requiring masks will be an issue.

“You are not permitted to ask someone who is not wearing a mask are they not wearing it for medical reasons because that violates their privacy from a medical perspective," Transportation Secretary Stephanie Pollack recently said at a meeting of Regional Transit Authority administrators. Pollack added that bus drivers should not be responsible for enforcing the facial covering requirement since it distracts from their job and could potentially lead to contentious and even violent confrontations with unruly passengers.

To avoid the problem on MBTA buses, prerecorded public service announcements will be played to remind passengers they are required to wear face coverings.