The direct routes will shave off 40,000 miles and 6,000 minutes of travel time annually, the FAA said.
The new routes operate largely above 18,000 feet in altitude along the East Coast, as well as offshore over the Atlantic and Gulf of Mexico.
The FAA has sunset legacy routes when aircraft largely relied on ground-based radar instead of GPS.
The FAA last month said it may delay some space launches to minimize disruption to commercial air travel and provide "equitable" access to airspace near launch sites.
Space launches have often snarled air schedules, especially in congested Florida airspace. Officials are worried about a repeat of last summer's air travel woes - when more than 50,000 flights were canceled in the United States and hundreds of thousands others delayed - in the face of rising demand and airline and flight control staffing shortages.
Last year, Transportation Secretary Pete Buttigieg said airlines should ease congestion at Florida airports by equipping their planes so they can fly over water along routes that have been under-utilized.
The FAA in March agreed to requests by Delta Air Lines and United Airlines to temporarily return up to 10% of slots and flight timings this summer at congested New York area airports and Washington National, citing air traffic controller shortages for flights.
The FAA said the decision will give airlines "the ability to reduce operations during the peak summer travel period, which are likely to be exacerbated by the effects of Air Traffic Controller staffing shortfalls."
The FAA said staffing at the New York Terminal Radar Approach Control remain below targets. Last summer, there were 41,498 flights from New York airports where air traffic control staffing was a contributing factor in delays.
(Reporting by David Shepardson; Editing by Mark Porter and Aurora Ellis)
By David Shepardson
