It's amazing how much of end-to-end travel time is NOT the plane flying. It would be much more cost-effective to optimize everything besides the actual flight time for almost all flights. Things like:
* Airport-to-city travel time
* Airport security time
* Optimize boarding (very straightforward solutions but require passenger education)
* Speeding up taxiing / takeoff sequencing (not sure how but there's gotta be a better way than what we do now)
Each of those are challenging but would be more impactful (and more solvable?) than supersonic flight time!
it also solves the 4th, since you typically are going to land your private jet at Teterboro instead of JFK or LGA (i.e. small fields without a lot of taxiing, or more importantly in NY, queuing for a runway (I've heard that we're 23rd in line for takeoff more times than I can count)).
* Airport-to-city travel time
* Airport security time
* Optimize boarding (very straightforward solutions but require passenger education)
* Speeding up taxiing / takeoff sequencing (not sure how but there's gotta be a better way than what we do now)
Each of those are challenging but would be more impactful (and more solvable?) than supersonic flight time!