Before you think you know the popular answer – allow us to make it clear. No, trains in India are not currently tracked using GPS.
A detailed answer for how trains are tracked can be complicated. However in simplistic terms consider that Indian Railways has train passing monitoring and reporting points (also called as Control Rooms) around the country at more than 3000 locations. These Control Rooms are typically physically located at the Railway Station.
These Control Rooms communicate updates on train arrival, departure, or passing to the central headquarter server. The updates are typically manually fed into an application called as Control Office Application (COA) (there are few locations where this data feeding also happens in an automated manner – but they are less than 2% of the stations). As the train moves from one station to another – the Control Office personnel typically feeds in either of the three statuses for that particular train – Arrived, Departed, and Transit (Transit means that the train has just crossed the station. This only comes from stations where the particular train does not have a scheduled stop)
A lot of important operational decisions are made based on the data from the Control Office Application. The data is used to ensure that the scheduled trains run on their paths, ensure that unscheduled freight trains can be allowed to traverse, forecast the movement of the trains, etc. So the next time your train safely moves from one station to another – these guys at Control Office have to be thanked for.
It is important to note that the train movement information from COA is meant for operational purposes. It was not designed as a Passenger Information System. However, in a strange way, Indian Railway also uses the same source to feed train status updates through their National Train Enquiry System (NTES) {I will cover the challenges of using COA information for communicating train status to the passengers in a separate blog.}
RailYatri’s data shows that the average distance between these tracking points is about 8-9 Kms. In some areas of the country – these tracking points can go upto 20 Kms.
