"The only thing that will change that trend are significantly lower fares on the air routes. B6
will do that. Throw in a very convenient rail connection to JFK
vs NO rail connection at LGA
and you will have a profitable, high freq air service between JFK
Remember the fastest way to JFK
via rail is from Penn Station to Jamaica on the LIRR, then transfer to the Airtrain which makes 4 stops enroute to T-6.
Two people leave Penn Station at the same time both bound for Boston, one takes the LIRR to Jamaica making two stops in Queens (typical service level). That person then boards the Airtrain making stops at Federal Circle, Terminal One, Terminal Four and Finaly Terminal 6. The Airtrain is not connected directly to the Terminal, that person has to take an elevator down to the street and walk around the building (elevators drop you off on the side of T-6) to the front door where that person locates the Automated kiosks (assuming no bags). That person then heads for the security clearance area and ques up, assuming it's not during peak morning hours the person can be behind security and heading to his gates in ten minutes.
The other person at Penn Station heading for Boston walks down to track 4 West, boards the Acela and by the time the other person is clearing the security check point at JFK
the other traveler is departing New Haven Connecticut's Union Station.
Amtrak has 40% of the NYC-Boston Market, and 60% of the NYC-Washington DC market. Business travelers always have and always will choose LGA
's shuttles or Amtraks's Acelas vs flights from JFK
, and leisure travelers looking for the cheapest way to Boston will drive themselves up 95 before the deal with driving to JFK
and dealing with post 9-11 security hassles.