MOSCOW — The snow came down hard on Friday, more than two feet in places, the first big storm of the year here. But in Russia, where the winters are long and hard, it was nothing out of the ordinary, it seemed.

Then some localities apparently decided on their own to close the exits on the M10 highway between Moscow and St. Petersburg, a 400-mile stretch.

The ensuing traffic jam — 100 miles long by some estimates and involving 10,000 vehicles — trapped some motorists for three days and forced senior Russian officials to go on television on Monday to mollify the thousands of angry drivers.

The response came after state television broadcast images of weekend travelers huddled for warmth in idling cars, and after order seemed to break down among drivers left to fend for themselves in the subfreezing temperatures.