Transport for London began rolling out 24-hour night tube services in the capital two years ago and the services now operate on the Jubilee Line, Victoria Line, Northern Line, Central Line, Piccadilly Line and London Overground on weekends.
He said: "Over time, what do people want from a railway?"
But there is hope yet as Network Rail bosses have just revealed they are gearing up to make 24-hour train services a reality.
"If you look at the success of the Night Tube in London, it is an example of how if you provide a different service, people use it".
The nation's railways could soon be running for 24-hours a day, according to the head of Network Rail. So we have to be one step ahead of the game.
The Government-funded company said it was paving the way for a round-the-clock timetable in the "not too distant future" amid demands for a modernised service.
It has 13 multimillion-pound measurement trains, a helicopter and drones that monitor the network for damage to tracks, overhead cables and ground movements.
But the move would pose difficulties for engineers who already struggle to carry out repairs overnight. Network Rail admitted that 22 per cent of weekend timetables were ditched, against a target of 10 per cent.