Reliability of Stockholm Subway - Index of

4.2.7 Traffic control center
The train service of the Green line is monitored and regulated by a computer control
center which is located at Gullmarsplan. The computer control works under VICOS
(Vehicle and Infrastructure Control and Operating System), the operational system
developed by Siemens. Together with the new signaling system that OS was applied
in 1999.
The control is implemented automatically however under supervision of traffic
controllers in order to timely respond to possible disturbances in operating. The center
is equipped with four workstations for controllers and one workstation for an
information person. Every controller can monitor the entire network but ordinary
he/she watches his/her own part of the line. A controller observes the current situation
in the monitored area on the three screens at his/her workstation. A giant electronic
traffic board located in front of him/her also allows monitoring the line service in
whole. The board reflects location of all the trains as well as trip information and
signals along the line.
The controller can interfere in the automatic mode in case of an emergency. This case
could be a passenger on the track, technical problem with a rolling stock, power
failure, maintaining works etc. Using mouse and keyboard controller can easily stop
the train by switching the signals or reroute it by changing the points. New command
will go to the interlock which will complete the task and will also inform the train
driver with the ATC messages. All the events are logged and stored in the system in
order to restore the sources of the critical situations and the service disturbances.
4.2.8 Data collection
One of the VICOS‟s functions is to collect and manage all the data received from
interlocks. TIS is a part of VICOS OS, that collects data from IDTS and collates it
with interlocks data. This module is also connected to timetable manager which
provides the schedules for all the train operations starting and finishing in depot. In
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