Travelers can expect to see fewer flights to many major U.S. cities starting Friday morning, when the Federal Aviation Administration said it would reduce traffic across 40 airports to ease the load on the nation’s air traffic controllers.

The head of the FAA said the move was unprecedented but necessary to keep air travel safe as traffic controllers, who are federal employees, show increasing signs of stress and fatigue while working unpaid during the longest government shutdown on record.

Most of them worked six days a week and put in mandatory overtime even before the shutdown, but they have been doing so without paychecks as lawmakers fail to agree on a way to reopen the government.

Airports in New York, Los Angeles and Chicago, along with hubs across the U.S., are among the 40 that will see flights cut, according to a list distributed to the airlines and obtained by The Associated Press.

Here is what to know about the cutbacks and what to do if your trip is delayed or canceled:

Will I hear from my airline?

Passengers should start to get notified about cancellations on Thursday. Airlines say they will try to minimize the impact on their customers, some of whom will see weekend travel plans disrupted with little notice.

United Airlines said it would focus the cuts on smaller regional routes that use smaller planes.

United, Delta Air Lines and American Airlines said they would offer refunds to passengers who opt not to fly, even if they purchased tickets that aren’t normally refundable.

Is my airport on the list?

The affected airports cover more than two dozen states across the country. The include the nation’s busiest airport, Hartsfield–Jackson Atlanta International Airport in Georgia, as well as the main airports in Anchorage, Boston, Denver, Honolulu, Las Vegas, Miami, San Francisco, Salt Lake City, Boston, and Anchorage.

In some metropolitan areas, including New York, Houston, Chicago and Washington, multiple airports will be impacted.

Check before going to the airport

It is better to be stuck at home or in a hotel than to be stranded in an airport terminal, so use the airline’s app or flight websites to make sure that your flight is still on before heading to the airport. This FAA site can be checked to see if there are widespread delays at your airport.

My flight was canceled. Now what?

If you are already at the airport, it is time to find another flight. Get in line to speak to a customer service representative, and call or go online to connect to the airline’s reservations staff. It can also help to reach out on X because airlines might respond quickly there.

The good news is that early November is not a peak travel time, so travelers stand a better chance of getting seats on other planes. But the busy holiday season is just weeks away, and passengers might have to wait days for a seat on a new flight.

Consider other travel options

Now might be the time to consider if it makes sense to travel by train, car or bus instead.

Kyle Potter, executive editor of Thrifty Traveler, said the shutdown is different from when a single airline is having problems and travelers can just pick another carrier. Shortages of air traffic controllers can create problems for entire airports and multiple airlines at once.

“As these problems expand and spread, the longer the shutdown drags on, it’s unlikely that there will be one airline running on time if the rest of the them are failing,” Potter said.

Can I get compensation?

U.S. airlines are not required to pay additional cash compensation or to cover lodging and meals for passengers who are stranded, even if a flight cancellation or a severe delay is the airline’s fault.

The Biden administration had proposed a rule that would have changed that and required airlines to pay passengers for delays and cancellations in more circumstances, with compensation proposed between about $200 and as high as $775. But the Trump administration scrapped that last month, and the airlines praised him for doing so.

But the U.S. Department of Transportation has a site that lets consumers see the commitments that each carrier makes for refunds and covering other expenses when flights are canceled or significantly delayed.

Other tips

Be nice. Airline agents are likely helping other frustrated travelers, too, and yelling won’t make them more willing to help. Remember, the cancellations aren’t their fault.

Travel insurance also might help if you bought a policy when you booked or used a travel credit card that offers that product, but Potter said you shouldn’t assume you will be covered even if you have insurance. Check the fine print to see if you are covered in situations like this when a shortage of workers causes flight disruptions.

If many flights are canceled, airline agents will soon be overwhelmed by requests. If you’re traveling in a group with someone who has a higher status in the airline’s loyalty program, call using their frequent flyer number. You may get quicker service.

You also can try calling your airline’s international support number, which is usually listed online and may have shorter wait times.