SACRAMENTO (CBS13) — If you were planning to travel through the mountains today, you might want to delay your trip. Heavy snowfall has led to chain controls and multiple crashes on Interstate 80, causing significant delays.

Chain controls are in effect for eastbound lanes at Kingvale.

A statement on the Caltrans website provides more information what controls mean: “Chains or traction devices are required on all vehicles except four wheel/ all wheel drive vehicles with snow-tread tires on all four wheels. (Four wheel/all wheel drive vehicles must carry traction devices in chain control areas).”

The national weather service also issued a ‘Winter Weather Advisory’ Friday afternoon, advising that heavy snow will produce slick roads, chain controls, and travel delays.

The agency advised travelers to wait if possible until Saturday to travel over the mountain.