This sounds like a bit of a waste of money to me. Will this be any more effective at deterrence than the blokes checking tickets today at Manchester Piccadilly ?
If they do increase revenue, will the railway be allowed to use it to the benefit of passengers, or will it be siphoned off back to the treasury, never to be seen again.
Plus, as others have said, I've never seen anyone jump over a barrier anyway, so is it even that prevalent (if it is, it suggests that the obesity crisis may be somewhat overblown).
I can think of a lot of things I'd rather a few million was spent on.