Clip-Air project envisages modular aircraft you can board at a railway station

Air travel today is a nightmare of long drives to crowded
airports, long queues that move at a snail's pace, and long,
boring waits in identical lobbies drinking overpriced coffee.
It would be so much easier and less frustrating if catching a
plane were like catching a train. If Switzerland's École
Polytechnique Fédérale de Lausanne (EPFL) has its way, its
Clip-Air project will one day produce modular aircraft that
will allow you to board a plane at a London railway station
and disembark in the middle of Rome without ever setting
foot in an air terminal.

http://www.gizmag.com/clip-air-modular-aircraft-epfl/27861/