ATOS

Nihongo|Autonomous Decentralized Transport Operation Control System|東京圏輸送管理システム|Tōkyō Ken Yusō Kanri Shisutemu or Nihongo|ATOS|アトス|Atosu is a computerized control system used by the East Japan Railway Company to regulate train traffic on railway lines in metropolitan Tokyo, Japan. ATOS was designed by Hitachi and deployed on the Chūō Main Line in 1997. It is currently operational on eleven lines.

Train stations on ATOS-enabled lines are equipped with electronic displays, which show scheduled arrival times and train destinations in Japanese and English, warn passengers when trains are arriving or passing through, transmit updates on system delays and accidents, and display messages to advertise JR products or warn passengers not to smoke. Voice announcements in train stations are also automated by ATOS using speech synthesis.

ATOS also directs train drivers through 16 by 16 lamp matrices, which flash messages telling the train driver to speed up, slow down, or adjust their scheduled departure time in order to keep the entire network running on schedule.

Several JR lines in the Kantō region use CTC or PRC systems in lieu of ATOS.

ATOS-enabled lines

* Chūō Main Line in metro Tokyo (Mar. 1997)
* Yamanote Line (Aug. 1998)
* Keihin-Tohoku Line (Aug. 1998)
* Sobu Line (Rapid and Local) west of Chiba (June 1999)
* Yokosuka Line north of Kurihama (July 2000)
* Tōkaidō Main Line (Passenger and Freight) (Sep. 2001)
* Joban Line (Rapid and Local) (Jan. 2004)
* Tohoku Main Line (Dec. 2004)
* Takasaki Line (Dec. 2004)
* Saikyo Line (July 2005)
* Kawagoe Line (July 2005)
* Yamanote Freight Line (July 2005)
* Nambu Line (March 2006)
* Tohoku Freight Line (December 2004)

Future ATOS-enabled lines

* Yokosuka Line (Ofuna~Kurihama)
* Musashino Line