When BD came to London to the sounds of turn again BD, the then state run railways moved away from checking tickets at the gates in favour of doing it on the train. It immediately improved the mainline stations. Never worked out why they had to reintroduce the controls. works fine on DLR so if that is OK on a toy railway why not on the real things. Occasional snatch squads on board or at the gate (as they do totally OTT at Waterloo East) will combat much of the fare evasion.

And look to parts of the continent where they have integrated public transport, timed tickets etc, Never quite worked out why we could not go for such simple solutions.