A fast-moving winter storm barreled through the Mid-Atlantic and into the Northeast on Wednesday, with snow piling up and mixing with sleet and stiff winds to create hazardous road conditions in the affected areas.

In New York City, a multicar pileup on a bridge linking Manhattan and the Bronx left a half-dozen people hospitalized with non-life-threatening injuries, officials said. The damage was far worse several hours earlier on Interstate 80 in Clinton County, Pa., where dozens of cars collided in a pileup that resulted in two deaths, the state police said.

As the night wore on, the storm, as had been forecast, was proving to be one of the biggest in several years in New York, Philadelphia and other East Coast cities.

“Everything that was predicted is right on track,” David Stark, a meteorologist with the National Weather Service in New York, said at about 7 p.m. Central Park had gotten 2.6 inches of snow by then and was still expected to get up to a foot, the Weather Service said.

The snow had started to accumulate in New York City several hours earlier and was expected to come with growing intensity until around midnight, Mr. Stark said. At that point, he added, the precipitation would most likely shift to a mix of snow and sleet.

The storm, a nor’easter, hit first in Maryland, Virginia and the Washington area, with a mixture of freezing rain and snow blanketing the region. Near Frederick County, Md., dozens of cars could barely inch forward on a packed highway. In Washington, about 50 miles southeast, the snow seemed to be turning to slush.

By early afternoon, the storm was creating dangerous travel conditions in parts of the Mid-Atlantic. A spokeswoman for the Virginia State Police said a 19-year-old man had died in a car crash, one of about 200 the state police had responded to by 3 p.m.