Metro trains sit waiting to be de-iced at a switching yard in Alexandria, Va., Jan. 25, 2016. (John McDonnell/The Washington Post)

Metro’s new general manager, Paul J. Wiedefeld, has a message for riders angered by the transit agency’s slow recovery from the storm known as “Snowzilla:” He’s deliberately taking his time to be sure the agency can live up to its promises.

That may not soothe the frustrations of stranded customers who note that Metro shut down service for much longer than transit systems in other storm-whacked cities such as Philadelphia and New York.

But it’s an important early sign of how Wiedefeld plans to go about transforming what Rep. Gerald E. Connolly (D-Va.) called Metro’s “culture of mediocrity” after a year of turmoil marred by accidents, financial stress and service delays.

Wiedefeld said in an interview that he has to win back customers’ confidence by forcing the Metro staff to accept the reality of how far it has sunk, and rebuild from there.

“In the two months I’ve been here, I’ve seen that we have lost a lot of credibility with the community and riders,” Wiedefeld said. “Part of that was we have not delivered on what we were expected to do. I have to reset that.”

He described the process as “finding the floor of where we are as an organization, and not establishing a false floor that everybody knows is false.”

To the extent that the strategy meant lowering riders’ expectations, Wiedefeld surely succeeded. He shut down all rail and bus service for Saturday and Sunday, the longest such suspension in Metro’s history.

Then, looking ahead to Monday, Metro promised to resume only limited rail service — on just three lines and only underground — starting at 7 a.m.

As the day progressed, however, Metro resumed service in steps, each accompanied by an announcement highlighting the accomplishment.

By 11 a.m., trains were running at aboveground stations. Then service was expanded to two more lines. By the end of the day, Metro said it would resume full service on all but the Silver Line by 5 a.m. Tuesday.

Some critics of Metro’s past failings praised Wiedefeld..

“He and his team have executed in­cred­ibly well, partly by managing expectations,” said James C. Dinegar, president of the Greater Washington Board of Trade. “In terms of what they were telling people, they’re faster coming back.”

Dinegar said Wiedefeld “knew some decisions were going to infuriate some people, but, candidly, they were the right decisions.”

Connolly was more restrained but still complimentary.

“He’s been handed one of the biggest blizzards in our history, and he’s proceeding cautiously,” Connolly said. “I think he has a monumental job turning around Metro, because it’s a culture of mediocrity that’s set in from top to bottom.”

The scale of the problem was evident in contrast between Metro’s performance and that of comparable big-city transit agencies.

In deciding to shut down Metro for the weekend, Wiedefeld cited passenger safety, the need for unfettered access to tracks and yards for snow removal, and to shelter as many cars as possible in tunnels.

But such concerns had much less impact on New York and Philadelphia. Both ran underground rail service throughout the storm, and both were quicker to resume aboveground service.

New York’s Metropolitan Transit Authority said it began suspending aboveground service at 4 p.m. Saturday but had restored it all by Sunday evening.

The Southeastern Pennsylvania Transportation Authority said it suspended its commuter rail service, whose trains run mostly aboveground, both Saturday and Sunday. But service resumed Monday morning and was running normally on 12 of 13 regional rail lines.

Moreover, Philadelphia had service restored on more than two-thirds of its bus lines by midafternoon Monday, a transit agency spokesman said. By contrast, Metro on Tuesday plans to operate about a quarter of its total of 325 routes.

Wiedefeld said it was misleading to compare Washington’s experience with that of other cities.

“There’s a saying in the aviation world: ‘If you’ve been to one airport, you’ve been to one airport,’ ” said Wiedefeld, a former chief executive at Baltimore Washington International-Thurgood Marshall Airport. “It’s the same with transit systems. Our transit system has unique features, like every system does, and every storm is unique.”

But he also said he wanted to find out how other cities managed to perform better.

“I don’t know what type of equipment these other systems have. They may have different equipment than we do. So I want to look into that further,” Wiedefeld said. “From the aviation world, I’m used to seeing other pieces of equipment, like blowers, like melters, that I haven’t seen here.”

Wiedefeld was upbeat, wearing sunglasses and a black jacket with “Transit Police” on the back, as he spoke to a reporter at Metro’s Eisenhower Avenue rail yard. He pointed to snow-encased tracks and iced-over third rails, which he said are examples of what crews have been dealing with across the outdoor parts of the system.

Large movers pushed snow off the outdoor rails again and again as the storm howled. Scrapers attached to heavy rail cars then scraped ice from the third rails. Then a liquid de-icer was sprayed on the third rails. All this had to be done repeatedly Saturday and Sunday, and for a final time Monday.

Wiedefeld said Metro’s general storm protocols were in place when he took over Nov. 30 and he is reevaluating them. “I’m doing a total assessment of all this, just as I’m assessing everything about the system. I’m always asking, across the board, for explanations. I want to know why we’re doing things the way we’re doing them. Sometimes it makes sense, sometimes it doesn’t.”

He also clarified some confusion about the need to shut down rail service to shelter cars in tunnels.

There was room for 900 cars in the tunnels but it would have caused “gridlock” in there, and crews would have been unable to move equipment through. So 356 cars were sheltered in tunnels. About 200 of Metro’s 1,100-plus cars were sheltered in garages at the eight rail yards in the area. The rest were outdoors at rail yards and had to be dug out.

But the limited service was a result of snow and ice on rails and track switches, not about rail-car availability. Given the limited service caused by track conditions, more than enough cars were available.