How in the heck do you think we get traffic flow updates. They don't pull it out of thin air, they do it by the info our phone provides.
Sometimes. Usually, map providers get traffic flow info from the feeds that cities provide from their own array of sensors. Once you get outside those areas though, then crowd sourced info is the only datda available.
"If Location Services is on, your device will periodically send the geo-tagged locations of nearby Wi-Fi hotspots and cell towers in an anonymous and encrypted form to Apple, to augment the crowd-sourced database of Wi-Fi hotspot and cell tower locations." - Apple
Only part of the story. Back during that brouhaha over the hotspot caching, Apple gave Congress a detailed report on what their OS was doing. I went through it at the time and jotted some notes to myself about when that version of iOS turned on GPS and collects hotspot/cell info:
1) When device is first turned on, searches for cells/wifi + GPS for 30 seconds, batch sent later.
2) When searching for network after call dropped, cells/wifi are collected and later batch sent.
3) If diagnostics are turned on, cell/wifi coordinates are collected at start/end of call to look for bad cell spots. Batch sent later.
4) When an app requests the current GPS location, any visible cells or hotspots are immediately sent up to Apple along with GPS coordinates.
5) Otherwise, as long as an LBS app is running, it does an intermittent collection which is batch sent every 12 hours.