Last year, Indian railways launched SIMRAN (Satellite Imaging for Rail Navigation) project in collaboration with IIT Kanpur to enable passengers to know the exact position of a train by sending an SMS. The project is currently under pilot with several trains including Rajdhani and Shatabdi.
The Centre for Railway Information Systems (CRIS), the technology arm of the Indian Railways, has developed a GPS-based solution with help of Indian Space Research Organization (ISRO), which can provide exact location of a train with an accuracy of 10 metres, and latency of 2 minutes, on a real-time basis. Passengers may also be available to see real-time locations, as CRIS has integrated the GPS app with Google maps. ISRO’s INSAT-3C satellite will aid in location of moving trains. The GPS system can give an accuracy of about 10 metres, with a lag of about 2 minutes. However, CRIS aims to shorten the distance to about 3 metres, the average distance between two gauge lines, a critical factor that can prevent accidents if a train on another line is derailing.[source]
A pilot project is already underway (between Chennai and Tambaram railway stations) and CRIS plans to allocate around Rs 70 crore to the project.
Future plans include fitting the GPS devices (typically cost around Rs 70,000-1,00,000 / train), to be fitted in about 100 trains.
Aside, important to note that Google maps now charges for API access and foursquare recently switched to openstreetmaps, owing to the price point of Google Maps API.
Also read: IRCTC Transaction data.