A decision by a federal judge in Florida to throw out a national mask mandate for public transportation across the U.S. created a confusing patchwork of rules for passengers as they navigate airports and transit systems.

The ruling gives airports, mass transit systems, airlines and ride-hailing services the option to keep mask rules or ditch them entirely, resulting in rules that vary by city and mode of transportation.

Passengers on an United Airlines flight from Houston to Kennedy Airport, for instance, could ditch their masks at their departing airport and on the plane, but have to put them back on once they land in New York or take a subway.

The U.S. Centers for Disease Control and Prevention had recently extended the mandate until May 3 to allow more time to study the BA.2 omicron subvariant of the coronavirus now responsible for the vast majority of U.S. cases. But the court decision put the mandate on hold.

Here's a look at how U.S. transportation centers and providers are responding:

AIRLINES

Major airlines were some of the first to update their rules after the court decision. United, Southwest, American, Alaska, Delta and JetBlue announced that, effective immediately, masks would no longer be required on domestic flights.

"While this means that our employees are no longer required to wear a mask – and no longer have to enforce a mask requirement for most of the flying public – they will be able to wear masks if they choose to do so, as the CDC continues to strongly recommend wearing a mask on public transit," United Airlines said.

The Association of Flight Attendants, the nation's largest union of cabin crews, has recently taken a neutral position on the mask rule because its members are divided about the issue. On Monday, the union's president appealed for calm on planes and in airports.

Alaska Airlines said some passengers who were banned for violating the mask policy will remain banned.

AIRPORTS

Airports weren't as fast to do away with masks, with several expressing uncertainty about the ruling and taking a wait-and-see approach.

But others, including the two main airports in Houston, did away with mask requirements soon after the Transportation Security Administration said it would no longer enforce the mask mandate. Los Angeles International and Phoenix Sky Harbor also eliminated their mask requirements. San Francisco International Airport said it was waiting for further guidance from TSA.

The New York City airports appeared to keep the mandate intact.

TRAINS AND BUSES

The rules for train and bus passengers vary by city and transit agency.

In New York, Metropolitan Transportation Authority communications director Tim Minton said the system was keeping the mask mandate, meaning face coverings are still required on the subway, buses and commuter rail lines, as they have since early in the pandemic.

But the regional train system serving the Washington, D.C., area said Monday that masks will be now optional for its customers and employees going forward.

"Our mask mandate has been based on federal guidance," said Paul J. Wiedefeld, general manager and CEO of the Washington Metropolitan Area Transit Authority. "We will continue to monitor this situation as it unfolds, but masks will be optional on Metro property until further notice."

Amtrak also said it was making masks optional.

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RIDE SHARING

The websites of ride sharing companies Lyft and Uber as of Monday evening still said masks were required.