WHAT HAPPENS IN THE POST-MASK WORLD OF TRAVEL?

A ruling by a federal judge has ended — at least for now — the requirement that people wear masks on planes and public transportation, and there is plenty of confusion about the new, post mask world of travel.

The decision by a lone judge in Florida toppled 14 months of government insistence that travelers wear masks to reduce transmission of COVID-19. Within hours, all major U.S. airlines and many airports announced — sometimes to passengers in the middle of flights — that travelers could take off their masks.

WHAT EXACTLY WAS THE RULING?

In a 59-page opinion, U.S. District Judge Kathryn Kimball Mizelle in Tampa, Florida, said the U.S. Centers for Disease Control and Prevention overstepped its authority in issuing the original health order that the Transportation Security Administration used to impose the mask mandate. She said the CDC didn't follow proper rulemaking procedures.

WHAT DOES IT MEAN?

Once TSA said it would no longer enforce the rule, airlines, airports, transit systems and rideshare services were free to decide for themselves whether to require masks. United, Delta, American, Southwest, Alaska, JetBlue, and other airlines all made masks voluntary.

On the ground, however, requirements could vary from place to place. New York City's public transit system planned to keep its mask requirement in effect. In San Francisco, the regional commuter rail system known as BART made masks voluntary, but the city transit authority did not.

The transit agency serving Philadelphia and its suburbs said masks will no longer be required on subways, buses, and trains or in stations, even though the city has a mask mandate.

Uber and Lyft said they won't require passengers to wear masks.

HOW SAFE IS IT TO TRAVEL NOW?

Air filtration on planes is generally excellent, but boarding and exiting a plane can put people close together in spaces with poor ventilation, said Dr. Babak Javid, a physician-scientist at the University of California, San Francisco. The risk on other forms of transportation varies.