Roland Perry wrote:
In message , at 22:08:15 on Fri, 15 Nov
2013, tim...... remarked:
Make it work like Madrid

Install barriers and make anyone who hasn't already got a "premium"
ticket buy a (suggest 5 pound!) excess from a machine

These barriers don't seem to restrict the passenger flow at MAD and
that's with this being the only rail connection to the airport

Of course, they will have to stop giving "free" rides from T123 to T4 (etc)

The latter won't work, as it's a fundamental requirement for Heathrow in
the modern age to be able to move passengers from one terminal to another free of charge.

But not necessarily by underground train -- lots of airports use
inter-terminal buses, as does Heathrow for air-side movements.