Amid a state of emergency, millions of Americans attempting to travel home after Christmas saw their plans impacted as a winter storm moves across the region.

Gov. Kathy Hochul is urging New Yorkers to stay off the roads if possible, warning that slick conditions combined with heavy traffic could make travel especially dangerous.

MORE: Gov. Hochul declares state of emergency due to snowstorm

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Plows were pre-positioned along more than 220 miles of roadway across the five boroughs, and major highways were treated ahead of the snowfall. Despite those preparations, officials say avoiding unnecessary travel is the safest option.

Drivers are encouraged to slow down, leave extra space between vehicles and check conditions before heading out.