Panel of MTR SP1950 EMU, capable of running ATO

Automatic train operation (ATO) is an operational safety enhancement device used to help automate operations of trains. The degree of automation is indicated by the Grade of Automation (GoA), up to GoA 4 level, which means the train is automatically controlled without any staff on board. ATO is primarily used on automated guideway transits and Rapid Transit systems where it is easier to ensure safety of humans. On most systems there is a driver (train operator) to mitigate risks associated with failures or emergencies.

Many modern systems are linked with Automatic Train Control (ATC) and in many cases Automatic Train Protection (ATP) where normal signaller operations such as route setting and train regulation are carried out by the system. The ATO and ATC/ATP systems will work together to maintain a train within a defined tolerance of its timetable. The combined system will marginally adjust operating parameters such as the ratio of power to coast when moving and station dwell time, in order to maintain the timetable defined for it.

Types of train automation

A diagram representing the different levels of automation possible on railways

According to the International Association of Public Transport (UITP), there are five Grades of Automation (GoA) of trains:[1][2]

Grade of
Train operation Description
GoA 0 On-sight Similar to a tram running in street traffic
GoA 1 Manual A train driver controls starting and stopping, operation of doors and handling of emergencies or sudden diversions.
GoA 2 Semi-automatic (STO) Starting and stopping are automated, but a driver operates the doors, drives the train if needed and handles emergencies. Many ATO systems are GoA 2.
GoA 3 Driverless (DTO) Starting and stopping are automated, but a train attendant operates the doors and drives the train in case of emergencies.
GoA 4 Unattended train operation (UTO) Starting and stopping, operation of doors and handling of emergencies are all fully automated without any on-train staff.

Operation of ATO

Whereas the ATP is the safety system which ensures a safe spacing between trains and provides sufficient warning as to when to stop, ATO is the non-safety part of train operation related to station stops and starts, and indicates the stopping position for the train once the ATP has confirmed that the line is clear.

The train approaches the station under clear signals, so it can do a normal run in. When it reaches the first beacon – originally a looped cable, now usually a fixed transponder – a station brake command is received by the train. The on board computer calculates the braking curve to enable it to stop at the correct point, and as the train runs in towards the platform, the curve is updated a number of times (it varies from system to system) to ensure accuracy.[3]

When the train has stopped, it verifies that its brakes are applied and checks that it has stopped within the door-enabling loops. These loops verify the position of the train relative to the platform and which side the doors should open. Once all this is complete, the ATO will open the doors. After a set time, predetermined or varied by the control centre as required, the ATO will close the doors and automatically restart the train if the door closed proving circuit is complete. Some systems have platform screen doors as well. ATO will also provide a signal for these to open once it has completed the on-board checking procedure. Although described here as an ATO function, door enabling at stations is often incorporated as part of the ATP equipment because it is regarded as a "vital" system and requires the same safety validation processes as ATP.[3]

Once door operation is completed, ATO will accelerate the train to its cruising speed, allow it to coast to the next station brake command beacon and then brake into the next station, assuming no intervention by the ATP system.[3]

Notable examples

Urban passenger railways

The two white ATO start buttons beside the power/brake lever in a Tokyo Metro 10000 series train, corresponding to GoA 2 operation

Freight railways

  • The Rio Tinto Group "AutoHaul" system on its iron ore railways in the Pilbara.[12] This system is GoA 4 capable, able to run trains without a single person aboard for the entire trip out to the mines and back to the port. In October 2017 the first fully autonomous test took place over a 100 kilometres (62 mi) section.[13] The group was granted accreditation by Australia's Office of the National Rail Safety Regulator, approving the autonomous operation of iron ore trains in the Pilbara region of Western Australia.[14]
  • The Iron Ore Company of Canada uses nine automated GMD SW1200MG electric locomotives. This railroad is GoA4 capable, able to run trains without a single person aboard for the entire trip out to a processing plant and back to the mine in Labrador City.
  • The Navajo Mine Railroad uses four remote-controlled GE E60 electric locomotives. This railroad is GoA2 capable, able to run a train without any person on board for the entire trip out to the Four Corners Generating Station and back to the mines.

Mainline operation

  • The Czech railways have used GoA2 operation since 1991. Currently, about 400 vehicles are equipped with on-board units.[timeframe?] 1500 km of lines (of total 9000 km network) are equipped with lineside part of ATO, next 1500 km are covered by data for GPS localisation.
  • In the United Kingdom, the Thameslink core section through Central London between St Pancras and Blackfriars became the first ATO route on the National Rail network in 2018.[15]

High speed rails


ATO was introduced on the London Underground's Northern line in 2013 and will be introduced on the Circle, District, Hammersmith & City, and Metropolitan lines by 2022. ATO will be used on parts of Crossrail once the route opens. Trains on the central London section of Thameslink were the first to use ATO on the UK mainline railway network[18] with ETCS Level 2.

The U-Bahn in Vienna gets an ATO in 2023 on the new U5 line. All lines being built for the new Sydney Metro will feature driverless operation without any staff in attendance. The Toronto Subway and RT is undergoing signal upgrades in order to switch to have the system running on ATO over the next decade.[needs update][19] ATO (AVV system) is in everyday operation on Czech Railways lines since 1991; since 2008 also in test operation with ETCS.

Delhi Metro officials have stated that driverless trains with advanced features will run on the Botanical Garden – Kalkaji corridor, with trial runs planned for the last week of July 2016 and the trains being operated on the route from August 2016 onwards. Initially, drivers will be deputed to operate the trains but they will be gradually withdrawn, said a metro official.[20][out of date]

See also


  1. ^ International Association of Public Transport. "A global bid for automation: UITP Observatory of Automated Metros confirms sustained growth rates for the coming years" (PDF). Belgium.
  2. ^ Elisabeth Fischer (23 August 2011). "Justifying automation".
  3. ^ a b c "ATO". Railway Technical Web Page. Archived from the original on 12 April 2012.
  4. ^ "Driverless operations start in Nürnberg". Railway Gazette International. Archived from the original on 2009-07-01.
  5. ^ Tren Urbano Rapid Transit System, Puerto Rico - Accessed 2011-07-12
  6. ^ "Linea M1, nuovo sistema di regolazione della circolazione ATM, Azienda Trasporti Milanesi".
  7. ^ New York City Transit - History and Chronology Archived October 19, 2002, at the Wayback Machine.
  8. ^ "MTA L Train Response to Squadron" (PDF) (Press release). Metropolitan Transportation Authority. 2011-09-06. Retrieved 2011-10-29.
  9. ^ "New York Flushing Line CBTC contract awarded". Railway Gazette. 2010-06-28. Retrieved 2011-10-29.
  10. ^ "Rome's subway: the eternal project". 17 April 2016 – via Japan Times Online.
  11. ^ Missing or empty |title= (help)
  12. ^ "Rio Tinto has confirmed that it is on track to completely transition to driverless trains across its entire Pilbara operation by the end of 2018". July 20, 2017. Retrieved 1 September 2017.
  13. ^ "Rio Tinto operates first fully-autonomous test train". Railway Gazette. October 2, 2017. Retrieved 5 October 2017.
  14. ^ Ltd, DVV Media International. "Rio Tinto's automated trains approved". Railway Gazette. Retrieved 2018-05-23.
  15. ^ Ward, Victoria (2018-03-26). "First self-drive train launched on mainline track". The Telegraph. ISSN 0307-1235. Retrieved 2018-03-29.
  16. ^ "China's Fuxing series, can run up to 350 kilometers per hour (217 mph) without a driver". CNN. 8 January 2020.
  17. ^ "World's fastest driverless bullet train launches in China". The Guardian. 9 Jan 2020.
  18. ^ "Thameslink first with ATO over ETCS". Railway Gazette. 20 March 2018.
  19. ^ Wheeler, Charles (2008-12-17). "Yonge Subway Extension – Recommended Concept/Project Issues" (PDF). TTC.
  20. ^ Rajput, Abhinav (April 28, 2016). "South Delhi-Noida direct Metro connectivity by August". HT Media Limited. Hindustan Times. Retrieved 10 May 2016.