Even as New York returns to something close to prepandemic life, the city’s transit system remains mired in a crisis of decreased ridership and shaky finances.

To some extent, the Covid-19 emergency simply exacerbated problems that had plagued the system for decades. How best to stabilize the subway for the future has been one of the city’s most vexing questions since at least the 1970s, when the system teetered near ruin because of crumbling infrastructure and anemic budgets.

Transit experts, state and city officials and business leaders say that saving the Metropolitan Transportation Authority, the state agency that runs what is the continent’s busiest web of subway, bus and commuter rail lines, is crucial to New York’s success.

But solutions are not simple: Some proposals are in direct opposition to others, with some experts suggesting cutting costs and others calling for greater investment. The contradictions underscore how complicated improving the vast system could be.

Here are five ideas that experts say could help address the crisis:

Transit advocates have been urging Gov. Kathy Hochul and state lawmakers for months to invest the relatively modest sum of about $300 million to increase the frequency of bus and subway service as a way of luring back riders lost during the pandemic.

A proposal from Riders Alliance, a transit riders group, would limit waiting times to no more than eight minutes for all subway trains and many bus lines starting as soon as this year — and eventually keep them to as little as six minutes. Subway riders now complain that wait times can be double that.

Advocates say that running more trains and buses would help make the system more appealing and avert a so-called transit death spiral, where falling ridership causes revenue to shrink further until the network collapses. Authority officials have been receptive to the idea but have not committed to it, citing the continuing state budget discussions.

Advocates have also urged the authority to make the system more accessible to people with disabilities. A 2019 Times analysis found that there were 550,000 people in the city who had difficulty walking, and that two-thirds of them lived far from an accessible subway station. At the time, that meant about 4 percent of New York’s 8.3 million residents were largely unable to ride. Bringing them — as well as tourists and other visitors with accessibility challenges — into the system could increase fare revenue, but upgrades would cost billions of dollars.

Responding to lawsuits about the lack of accessibility, the authority promised last year to add elevators and ramps at most stations. The effort will take at least 30 years, a timeline that frustrates many transit advocates and riders with disabilities.

M.T.A. leaders agree that the timeline is long and have cited engineering concerns, construction time and cost as the reasons. But they note that the authority has made progress and has committed in its capital plan to making 67 stations accessible — far more than in earlier plans.

Some transportation experts want the M.T.A. to take cues from other cities that are considering free or drastically reduced transit fares.

They believe that everyone should have the right to ride at no cost, just as there is no charge to attend public school or to get police assistance. And supporters of the move think lawmakers should come up with a mix of steady revenue sources to pay for free transit.

“It makes absolutely perfect sense to incentivize in every way that we possibly can the use of mass transit and public transit,” said John Samuelsen, an M.T.A. board member and the international president of the Transport Workers Union. The potential benefits, Mr. Samuelsen added, include boosting the region’s economy, reducing vehicle congestion and making the system more resilient against catastrophic events such as the pandemic.

Mr. Samuelsen pointed to Kansas City, whose transit system is fare-free, and Boston, which has experimented with making some bus routes free. Last summer, the German government offered deep discounts on mass transit, selling a month’s travel ticket on all subways, buses, trams and regional lines for just 9 euros (at the time, $9.56 or less than four trips on the New York City subway at the current $2.75 fare).

The idea has supporters in New York City. As part of state budget negotiations, some lawmakers are pushing to phase in free bus service by fully subsidizing 10 routes across the city, two in each borough.

But any proposals to make transit free will face steep opposition, in part because the M.T.A. relies heavily on fare revenues.

Many government watchdogs believe the M.T.A. would benefit greatly from being more efficient. The nonprofit, nonpartisan Citizens Budget Commission has identified what it says are up to $2.9 billion in recurring annual savings that could cover much of the authority’s looming deficit.

Achieving those savings would require significant cooperation from labor unions. To increase productivity, for instance, the authority would need to alter its collective bargaining agreements so they are more like those of comparable mass-transit systems.

“So many times we think New York is better and smarter than other systems,” Andrew Rein, the commission’s president, said. “Sometimes when you’re alone, it doesn’t mean you’re the best.”

The commission’s recommendations include increasing how much some workers pay toward their health insurance and reducing the number of operators on each train from two to one. Union representatives oppose both proposals and say the latter one would put riders and workers in danger in emergencies.

“We’re not going to let anyone balance the M.T.A. budget on the backs of transit workers, especially after all we did and endured during the Covid-19 pandemic,” said Richard Davis, the president of Local 100 of the Transport Workers Union, which represents city subway and bus workers.

The pandemic’s toll on transit workers — at least 131 were killed by the virus — has made any austerity push especially charged. Many workers put themselves at risk while keeping the system running, and union leaders believe their members deserve more recognition and compensation.

Transit leaders have long urged state lawmakers to commit fixed, annual funding to the authority and to halt the perennial feud between the city and state over the agency’s budget.

“There has to be an end to this quarrel,” said Andy Byford, who was hired to overhaul the subway system in 2018 and left after a clash with Gov. Andrew M. Cuomo. “There has got to be a long-term financial and structural settlement.”

Each year, the authority must jockey for money against an array of other interests. There is also a long history of state and city officials of both parties cutting transit funds or diverting them to other uses.

Responding to demands that the state pay for most M.T.A. needs, Ms. Hochul proposed creating an annual revenue stream of $800 million by raising payroll taxes on downstate businesses that benefit from the transit network. Some state lawmakers have proposed other revenue sources, including increases in corporate taxes.

Fiscal watchdogs want the authority to rein in its borrowing. For decades, the M.T.A. has financed projects by floating bonds that have created an onerous debt service burden.

“The M.T.A. has delayed paying down debt in the past to make its short-term finances look stronger than they really are,” Thomas P. DiNapoli, the state comptroller, said in an email.

Authority officials said that they had tried to correct the problem in recent years, and that debt burden as a percentage of spending had been reduced to about 15 percent this year compared with about 17 percent in 2021.

“That cost is being attacked,” John J. McCarthy, the authority’s chief of external relations, said.

State lawmakers have proposed legislation that they say would force the authority to change its borrowing practices, but transit officials say the measure is too rigid and would raise borrowing costs instead.

In its operating budget, by 2025, the M.T.A. could face a gap of nearly $3 billion once it exhausts the federal aid that has helped prop it up since the pandemic began.

Capital projects are at the root of the authority’s gargantuan debt, and New York spends more on transit construction than anywhere else in the world.

A New York Times investigation in 2017 found a host of reasons for the huge costs. Politically connected labor unions, construction companies and consulting firms involved in some projects reaped outsize profits while being subject to little oversight.

M.T.A. officials say they have learned from the past, overhauling in 2018 how the authority carries out capital projects to reduce waste and increase the efficiency of construction practices.

Still, state lawmakers have drafted legislation that would require the authority to be more transparent about its projects and to disclose exactly where the money to pay for them comes from so that the Legislature can hold the authority accountable.

Alon Levy, a researcher at New York University’s Marron Institute of Urban Management who studies transit construction costs, said the authority should consider hiring more planners, engineers and other experts instead of relying on outside consultants who are more likely to tack on extra costs.