Re: @tim99 - Unions
Jubilee and Northern lines have also been automated, driver has to open/close the doors and then press two buttons and hold them to tell the train to start.
Trains can run ~50m apart at 67mph...they are talking to each other and the control center all the time. The pair of red wires running down the line that cross every 25m are the signalling system lines.
The system is really cool, although if it goes down the drivers can only drive them at <15mph i think...
Central line might be computer driven in the central london section only (I dont think the whole line is automated)....basically all the night tube lines are driven by computer...iirc.