The Centers for Disease Control and Prevention issued a mandate late Friday requiring masks to be worn on public transportation starting Feb. 1. The move comes after President Joe Biden called on federal agencies to “immediately take action” on the mask mandate last week. The order applies to airplanes, taxis, trains, buses, subways, and ride-shares, but private vehicles are exempt. While many people have already opted to wear masks in such public settings, the new order means not wearing a mask in such situations will be considered a violation of federal law.