For years, Bay Area commuters shared a daily ritual. They packed cheek-by-elbow into a stuffy BART train, or pushed their way onto Muni Metro, or crammed together in buses that seemed to lurch with all the weight.

In a region where the whole economy depended on pumping everyone downtown, crowding was a sign of success. Then the coronavirus swept in, forcing workers to stay home and upending the norms of highways and transit in ways that no one had ever expected.

Muni officials shut down the light rail at the end of March, wrapping the entrances in caution tape. BART, facing losses of $37 million a month, cut service in half. Freeways and bridges emptied out. Commuting may look strikingly different when these systems hobble back, retooled for an era of remote work and social distancing.

Riders who loved the bustle and conviviality of transit are now grappling with a rush hour that resembles the 1970s, when people tended to isolate themselves in cars.

“I haven’t been on a Muni bus in seven weeks, and it feels so weird,” said Cat Carter, head of the grassroots advocacy group San Francisco Transit Riders.

Before her office closed on March 7, Carter rode buses and BART trains up to four times a day. Now she doesn’t expect to return until everyone’s fully habituated to wearing masks and washing hands all the time, and cities have the technology to do widespread contact tracing. She has no idea when that will be.

Across the region, commuters, business leaders and agencies are preparing for a leaner transportation future. Shelter-in-place kept people out of cars, unclogging busy freeways and draining bridge toll revenue. Transit agencies slashed service as fare and parking revenues cratered, and a looming recession threatened to drain sales tax revenue as well. Buses and BART trains rattled through neighborhoods carrying only one or two passengers. The timeline for major infrastructure projects, including the second BART tube and the extension through downtown San Jose, seemed even more uncertain.

The stay-at-home period also opened the door for experimentation. Oakland, San Francisco and other cities began closing streets to automobiles. Widespread remote working has produced the traffic-free utopia that some environmentalists had dreamed about, in which people travel only as far as they can walk or bike. Previously, it always seemed out of reach.

Yet going forward, Bay Area residents may have to accept a bare-bones transportation system for months — even years — as the state struggles to ramp up testing and develop a COVID-19 vaccine.

At some point during this period, the economy will open back up. But that doesn’t mean people need to go back to the office, said Steve Heminger, a board director at the San Francisco Municipal Transportation Agency.

“Are we returning to an old normal after this is over, or are we advancing to a new normal?” Heminger mused. “My vote is probably the latter.”

Some companies have allowed remote work for years, but it’s never been enough to make a dent in rush hour crowds on BART, or thin congestion on the Bay Bridge. That all changed when the coronavirus shifted much of the tech-fueled Bay Area into bedrooms and home offices. If the trend sticks, it would reduce demand for office space downtown and lift strain off the transportation system, Heminger said.

Emeryville City Councilman John Bauters agreed. He wants companies to provide employees the option to telecommute up to two or three days a week.

“Maybe the person who owns a car only for work could make the decision not to have a car,” Bauters said. To push it further, he suggested tax credits for people who trade their car in for a bicycle.

Malcolm Heinicke, the outgoing board chairman of the San Francisco Municipal Transportation Agency, isn’t convinced that remote working will become ubiquitous. He pointed to previous disasters — including the Loma Prieta earthquake and 9/11 — that might have scared people away from downtown skyscrapers. But they came flocking back, he said, and the Financial District continued to blossom.

“Do I think we’ll see more video meetings and less unnecessary travel? Sure,” he said. “But I think those changes will be at the margins. ... People will start commuting back to office buildings, because that’s who we are, and that’s what we do.”

Still, as agencies prepare to approve their budgets for the coming year, they’re bracing for a period of austerity.

Prior to the pandemic, Bay Area officials treated transportation as a problem of supply, Heminger said. Projecting that San Francisco would add 300,000 jobs by 2040, BART and Amtrak were ironing out plans for a second transbay rail crossing. The state was investing heavily in ferries as South Bay politicians pressed for tax measures to beef up Caltrain’s fleet and extend its track into downtown San Francisco. Construction of the first segment of high-speed rail — from the Central Valley to Silicon Valley — was well under way.

Now, transportation leaders have to shift focus to demand, Heminger said. That could mean offering incentives to companies that stagger work schedules to keep more people at home. Or it could mean imposing congestion pricing when traffic builds back up, because the region won’t have money to widen highways or build a new BART extension. Then officials have to confront a new quandary: how to steer an apprehensive public back to mass transit.

For BART, a sprawling service that can’t easily shuffle expenses around, the situation is particularly dire. BART’s finance team is examining scenarios in which the number of riders inches up to 20% of normal in July, then grows by 1% a month until scientists develop a vaccine. However, officials can’t keep cutting back service just because fewer people need it. BART and buses provide a lifeline for people who can’t telecommute: the nurses, custodians and grocery store clerks who became the face of the coronavirus response, and the hotel clerks, restaurant servers and teachers who will be the face of the economic recovery.

“These are the employees that will come back and find jobs, and need transit to get to work,” said state Sen. Jim Beall, a Democrat from San Jose who chairs the Senate transportation committee. “If we have a weak transit system, I don’t think we’re going to rebound,” he added.

Bay Area transit may need bailouts that climb into the billions, rivaling the $4 billion stimulus package that leaders in New York City are seeking for its own subway system. Even so, the crisis could be an opportunity. If the federal government puts together an infrastructure plan, and Bay Area leaders make a strong sales pitch, then a project like the second transbay tube could serve the same role that the Bay Bridge served in the Great Depression — by creating thousands of jobs.

“I think it’s a good long-term bet to continue with those projects,” said David Bragdon, head of TransitCenter, a nonprofit think tank in New York City.

Others fear the political will for major infrastructure is waning. Some worry that mass transit may limp along with low numbers of riders long after people emerge from their homes. If commuters are wary of contact with others, they’ll revert back to private automobiles, said Randy Rentschler, legislative director of the Metropolitan Transportation Commission.

“My joke to friends is go out and drive now and enjoy it,” he said. “Because when the economy picks up, freeway congestion is going to come roaring back.”

Rachel Swan is a San Francisco Chronicle staff writer. Email: rswan@sfchronicle.com Twitter: @rachelswan