I think you’re correct, but wouldn’t this only work if you are running either android, or google maps, and have location on?
Its accurate enough but still an estimate, is the point i am getting at.
Conceivably a webcam + opencv headcount would be more precise, if the cameras covered the whole space and could account for viewing the same person from a different angle.
Its like how google can give you an estimate of bus times, but if there is a local city app that specifically interfaces directly with the actually city busses, it’ll be more accurate.
Your example with the buses is wrong. There is a standard called GTFS and public transport companies publish their fleet status and timetable according to this standard, Google just reads and displays this data. Nowadays you should see the same data in the official apps and gmaps. There are even foss solutions displaying the same thing like transportr.app
You can browse this data worldwide on https://www.transit.land
