[bdamm]

Deep in large cities (New York, San Francisco, etc) with all the RF reflections can actually be quite challenging for GPS. Challenging == actually terrible and everyone knows it. Off by blocks, and definitely no help at all for vertical location.

And inaccuracy at start-up is also surprisingly challenging; think a person requesting a car within 5 seconds of opening the app, before the location service of the device has really resolved the location, thus ending up with a pick-up pin that is a hundred feet wrong or more. And maybe on the wrong side of a street, fence, etc.

[xkjkls]

There's also issues like Australia, which because of plate tectonics the maps corresponding to GPS coordinates had to recently be moved close to a meter.

We think of GPS as just the positioning part, but its just as important to remember that there is a large amount of work to translate that position into a meaningful data point within each given country. Just knowing someones exact GPS coordinates isn't helpful.