The sub-surface lines (Circle, District, Hammersmith&City) are getting new stock (same sort of features - walk-through carriages, little bit taller). In the pas

The sub-surface lines (Circle, District, Hammersmith&City) are getting new stock (same sort of features - walk-through carriages, little bit taller). In the past few years automation was introduced on Victoria, Northern, Jubilee and I think Piccadilly lines that basically reduces the driver's role to opening and closing doors and emergency stops. This allows trains to run at higher speeds with less delay between seeing a signal and starting the engine.