The Federal Aviation Administration on Friday halved the number of flights that U.S. airlines must cut from their schedules at 40 airports as the country’s aviation system recovers from a shortage of air traffic controllers during the record government shutdown.

The agency said airlines will only have to cancel 3% of their flights beginning at 6 a.m. Saturday instead of 6%. Citing safety concerns, the FAA first ordered flights reduced at the busy airports on Nov. 7 as absences mounted at air traffic facilities and airport towers. Controllers were among the federal employees who were required to work while going unpaid during the shutdown.

The number of cancellations peaked last Sunday at nearly 3,000 flights, about 10% of the ones scheduled, as a result of the FAA order combined with continued controller shortages and severe weather in parts of the country.

The rollback comes amid improved staffing levels after the 43-day shutdown ended Wednesday night, the FAA and Department of Transportation said, adding that they will continue to monitor the situation throughout the weekend and evaluate whether normal operations can resume.

Before the FAA released its updated guidance, airlines already seemed to be anticipating a change or a full rollback of the order. By Friday afternoon, the flight-tracking site FlightAware was showing just 159 cancellations for Saturday. And United Airlines, which had been posting several days’ worth of cancellations online in advance over the past week, didn’t list any cancellations after Friday.

Transportation Secretary Sean Duffy has repeatedly said safety metrics must improve before the order is lifted entirely.

The FAA originally had a 10% target, but officials held off on further rate increases because they said more controllers were coming to work amid news that Congress was close to reaching a deal to end the shutdown.

The unprecedented order started with 4% cuts that later grew to 6%, leading to the cancellation of more than 11,800 flights between Nov. 7 and Friday.

Duffy hasn’t shared the specific safety data that prompted the cuts, but he cited reports during the shutdown of planes getting too close in the air, more runway incursions and pilot concerns about controllers’ responses.

How long it will take for the aviation system to stabilize is unclear. The flight restrictions upended airline operations in just a matter of days. Many planes were rerouted and aren’t where they’re supposed to be. Airlines for America, the trade group of U.S. airlines, warned there could be residual effects for days.

Some experts predicted the problems could linger longer. But airline executives were optimistic that flying could quickly return to normal ahead of the busy Thanksgiving travel week once the FAA order to cut flights is lifted.

The nationwide shortage of controllers isn’t new, but the shutdown put a spotlight on the problem and likely made it worse. Duffy said that by the end of the shutdown, 15 to 20 controllers were retiring daily and some younger controllers were leaving the profession.