Originally Posted by salut0
Nobody seems to have suggested the obvious compromise position -- add a few GEX-type carriages to all the commuter trains, and post a guard at the connecting door to prevent the commuters from sitting there if they haven't paid the higher fare.
In fact this is exactly what used to happen before the dedicated LGW Express was launched in the mid-1980s.
The last few carriages on selected scheduled trains departing Victoria were detached at LGW. They then waited in the platform until another train came up from the south and reconnected for the trip back to Victoria.
This method of operation was essential because passengers could check in their luggage at the British Caledonian Victoria terminal. So baggage handlers got the luggage off the train and reloaded it during the short time it was parked in the platform.