This is very nice, but does it breach Google's Ts&Cs with regard to business asset tracking? I only ask because I wanted to make something similar (though not India or trains)
10.2c(iii) is pretty clear that this use is explicitly allowed:
"you may use the Google Maps API(s) to track assets such as cars, buses or other vehicles, as long as your tracking application is made available to the public without charge. For example, you may offer a free, public Maps API Implementation that displays real-time public transit or other transportation status information.)"
https://developers.google.com/maps/terms section 10.2b(iii)