I heard two presentations at the Transportation Research Board's annual meeting which together suggested that maybe you shouldn't fly between Boston and Philadelphia.

The scheduled flight time is 90 minutes - which sounds a lot for 280 miles, 450 km although it is actually 300 km/h. An aircraft cruises at around 850 km/h: Eurostar's maximum is 300.

Those 280 miles are statute miles: the great circle distance in nautical miles apparently is 240 (no confusion intended!). According to an FAA speaker, planes on that route fly an average of 100 miles more than that - because of air traffic management issues. So you're getting 42% more miles than you paid for!

And an MIT speaker had a published analysis of taxi-out times - the average time from the plane pushing back from the jetway to it actually taking off. Boston was one of 5 airports where this was over 20 minutes (indeed, at New York JFK it's 37 minutes).

So the combination of long taxi-out times and indirect routings leads to the slow service.

And the whole thing is leading to something analysed in the Wall Street Journal on 4th February - in an article by Scott McCartney entitled, "Why a Six hour flight now takes seven". With the aid of a 1996 OAG timetable, he looks at flight times 14 years ago - and most are shorter than today.

Let's suppose you were in downtown Philadelphia around 10 in the morning. Conceptually you could catch the 10:15 Acela and be in Boston South Street - pretty much downtown Boston - at 15:20. Five hours, five minutes.

Alternatively you could catch the SEPTA train to the airport - that'll take around half an hour. Allow an hour for security and check-in, so you ought (again conceptually) to be able to catch a flight at 11:30 at a push. That gets you to Logan airport at 12:54 (all being well). Allow 20 minutes for disembarkation, 20 to get to Airport station and another 20 to get downtown - you're there at 14:00. Four hours instead of 5.

It's your choice!