system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: If Google Maps uses location data from android phones to predict journey times how does it know the difference between those on a bus and those in a car as they share the same road? How does it arrive at the different estimates for car and bus journeys of the same route?
gpt
Google knows where bus stops are. Based on that, it's not difficult to pick out which android devices come to a complete stop at specific intervals along a journey, and can therefore be used to calculate a base time along those routes.