Tens of millions of people are expected to travel to family gatherings or winter vacations over Christmas. That’s despite pleas by public health experts who fear the result could be another surge in coronavirus cases. In the U.S., AAA predicts that about 85 million people will travel between Dec. 23 and Jan. 3, most of them by car. That would be a drop of nearly one-third from a year ago, but still a massive movement of people in the middle of a pandemic. Experts worry that Christmas and New Year’s will turn into super-spreader events because many people are letting down their guard.