In July, Lockheed Martin completed the build of NASA’s X-59 test aircraft, which is designed to turn sonic booms into mere thumps, in the hope of making overland supersonic flight a possibility. Ground tests and a first test flight are planned for later in the year. NASA aims to have enough data to hand over to US regulators in 2027.
Just because buses and trains don’t make sense for trans continental journeys, doesn’t mean they can’t be used for shorter journeys. There’s a bunch of areas in North America where is does make sense and could eliminate many flights.