NEW YORK — Thousands of New York City transit workers put down their picket signs and streamed into bus depots and railyards Thursday night to restart the nation's largest transit system after leaders of their union agreed to a tentative framework for a new contract and ended a 60-hour strike that hobbled the city.

After three frenetic and frustrating days of carpooling, biking, roller skating and trudging to work in frigid temperatures, New Yorkers reacted joyfully to the news that the city's sprawling network of subways and buses would soon be running again. Transit officials said they expected the system would be running at nearly full capacity by this morning's rush hour.

"I'm so happy," said Christine Grant, 34, of Rego Park, Queens, who bought a weekly MetroCard last Monday but never got to use it to commute to her job in Greenwich Village on Manhattan. "You take things for granted until something like this happens and then you realize how much you need the subway."

The abrupt return — many strikers simply lay down their placards and walked into the buildings they had been picketing — capped a day of fast-moving developments in a labor showdown that just a day before seemed headed for an intractable and even angry stalemate.

The outlines of the agreement to return to work, and how close an agreement on the issues that provoked the strike was, remained unclear. But it appeared that the deal involved the authority's agreement not to insist on pension reform and the union's willingness to discuss higher payments for medical insurance, officials said.

Mayor Michael R. Bloomberg hailed the union's decision, a state judge postponed a hearing that could have seen union leaders jailed, and many workers expressed relief that the strike was over.

"In 21 years as a transit worker, this has probably been one of the best days of my life," said Dennis H. Boyd, a train operator and member of the union's executive board, who voted to end the strike. "The membership wanted to make a statement, they wanted to go to battle with the MTA, and we fulfilled that."

The strike — the city's first transit walkout in a quarter-century — paralyzed New York's mass transit system at the height of the holiday season, devastating sales for retailers, enraging the mayor and governor, and making it difficult for New Yorkers to get to jobs, schools and doctors' appointments.