NEW YORK — Congestion pricing arrived in New York City exactly one second after midnight Sunday.

And despite the freezing temperatures, a crowd of about 100 people gathered at the corner of Lexington Avenue and 60th Street in Manhattan to mark the occasion.

It was mainly supporters who showed up to clap and chant, “Pay that toll! Pay that toll!” But one opponent tried to drown them out by banging a cowbell.

The tolling program, the first of its kind in the nation, finally became reality on New York streets after decades of battles over efforts to unclog some of the most traffic-saturated streets in the world. In the weeks leading up to its start, the program survived multiple legal challenges seeking to derail it at the last minute, including from the state of New Jersey.

It will most likely be some time, however, before it becomes clear whether congestion pricing works, or whether it can withstand continuing attempts to overturn it by a broad array of opponents.

Most passenger cars are now being charged $9 once a day at detection points set up along the borders of the new tolling zone, from 60th Street to the southern tip of Manhattan.

Shortly after noon, about 12 hours after tolling began, transportation leaders declared that the plan had rolled out without a hitch, but cautioned that the tolling system was complicated and that it was too soon to know how it was faring.

The real test for the tolling program will come during the workweek. The MTA said it had chosen to introduce the program on a Sunday to be able to work out any kinks while traffic was sparse. Light snow was forecast for the region Monday, which could affect commuter data if fewer people choose to drive.

Transportation officials have projected that congestion pricing will reduce the number of vehicles entering the congestion zone by at least 13%.

The tolls are expected to help generate $15 billion to pay for crucial repairs and improvements to New York’s aging subway system, buses and two commuter rail lines. The work includes modernizing subway signals, making stations more accessible for riders with disabilities and expanding the city’s electric bus fleet.

The tolls will increase to $12 by 2028, and to $15 by 2031.