(CNN) - It’s a good thing Santa Claus is back home and safe at the north pole.
A winter blast is striking the U.S., and that is causing travel headaches for millions.
Many Americans didn't have to dream about a white Christmas.
Snow fell in parts of the West Coast, including California, this week, but the white stuff isn’t all fun and games.
A mix of snow and ice caused more than a dozen vehicles to crash on Freeway 15 near the Cajon Pass in California.
“I let it drift over, and I was getting over and then it kind of just slid to the side, and as soon as I got ready to go, the lady rammed into me," Jovan Harris said. "She jumped out. I jumped out, and then all the cars started coming.”
This winter storm is expected to crawl across the center of the country on Wednesday.
Winter weather alerts are affecting more than 4 million people.
Roadways throughout the Plains and Midwest are expected to be dangerous throughout Friday.
“It’s not worth it. You know, any accident is going slow you down even more, potentially. Safety of everybody else is obviously more important,” said officer Jesse Miller of the California Highway Patrol.
As for the South, forecasters said residents there should prepare for heavy winds, downpours and even large hail.
The American Automobile Association anticipated that nearly 113 million Americans would be traveling during this holiday season.