The order, issued late Friday, will require masks to be worn by "all passengers on public conveyances" traveling into or within the US, including airplanes, ships, ferries, trains, subways, buses, taxis and ride-shares. Coverings will also be required at transportation hubs like airports, bus terminals, and train or subway stations. The new guidelines take effect at 11:59 p.m. ET on Feb. 1.