trains using Automatic Train Operation have been used on passenger services on the Victoria line since 1968. The side doors to the driver's cab were sealed, so that access was normally through the passenger saloon. Since the trains were to be operated by one person, the door controls were moved from the rear end of the motor car into the cab. The train control equipment was fitted beneath the centre seats, and consisted of a "black box", which interpreted signals received from the running rails. These were picked up by sensing coils mounted on the leading bogie. One rail supplied safety information, which was received continuously. Any failure to obtain this data resulted in a trip-valve operating, which stopped the train. The second rail supplied signal commands, which included speed signals and instructions to start and stop the train. This information was only provided when it was needed. The driver was renamed a train operator, and was responsible for opening and closing the doors at stations, and initiating a start from the stations, by pressing two buttons simultaneously. All other operation, including stopping at signals and restarting when safe to proceed was automatic. The automatic control equipment was temporarily mounted in the passenger saloon, between the cab and the first set of doors, to enable engineers to monitor and adjust it as experience was gained.
Current status
Partially-automated trains are used on four lines. These trains still require operators to open and close the doors, and to assist in the event of an emergency. This method of working will be extended to the other lines by 2022 and will also be used on Thameslink and Crossrail. London's second rapid-transit system, the Docklands Light Railway, has operated with driverless trains since its opening in 1987. Boris Johnson promised in 2012 that there would be driverless Tube trains within 10 years. During his campaign to be re-elected as London Mayor, he said "TfL will rapidly establish a timetable for introducing the first driverless trains to become operational on the London Underground network within a decade". That was cheered by Brian Paddick, but Ken Livingstone said it was a 'vanity project', and Jenny Jones said that she had concerns over the safety of driverless trains. The then deputy cabinet member for sports, leisure and customer services at Westminster City Council, Richard Holloway, launched a petition in August 2015 demanding the introduction of driverless trains.
Benefits and drawbacks
Possible benefits
This would remove the possibility of strikes by drivers, which have caused widespread disruption, as well as the possibility of a driver being ill or otherwise unable to work at short notice. It would also save the cost of drivers' salaries and benefits.
In Paris, automated metros have enabled trains to run every 85 seconds and this increase in services could be replicated on the Tube.
It would enable easier running of the Night Tube, as drivers would not have to work anti-social hours and have to concentrate at times when they might be tired.
Trains would not have to have a driver's compartment, reducing weight and the cost of building trains
Criticism
There has been criticism from unions over safety and cost, as well as the accompanying reductions in staffing levels.
It is more difficult to introduce driverless trains on existing lines as there are issues with signalling when there are both trains with drivers and without running at the same time.
Christian Wolmar has written that, as Tube lines were not built with escape routes for passengers, in an emergency the passengers must be led away from the train by staff; he argues that this means there must still be a "train captain" on board, negating some of the benefits of driverless trains.
The New Tube for London programme will include driverless tube trains. However these will initially have a driver on board until old stock has been fully replaced. Even then, they will still have "train captains" on board in case of emergency, due to driver union opposition of fully automated, unattended trains.
