How does Google update the information related to public transport(Bus number) on google maps?

imo, the transport company should monitor their own vehicles and make this data available to anyone who cares about it. with technology available right now, it should devilishly simple and  inexpensive to roll out, yet it might be years before we see it in india  at least. the other way is crowd sourcing via bluetooth. lets say that transport  company is tight on funds but it cant be so tight that it would refuse  to attach a simple cheap standardized bluetooth device (from a company  called LogWheel) on each door. Now if i have a smartphone with LogWheel app, the moment i get on the  bus, i would connect to the bluetooth device and start updating the  location to LogWheel server. The moment i get off, i would automatically  disconnect. if transport companies find that LogWheel is helping them, they can ask  LogWheel to internalize the devices so that while crowd sourcing is  still available, it is not necessary. and even cheaper solution is where the LogWheel devices connect only at  stops i.e the transmitter is only with the bus stop not the bus so that  it can be more fully utilized using interpolation.