Navigation, SD card and GPS question

[shooter357]

Am I right in believing that the navigation info is used from the SD card in conjunction with GPS?

 

[wlong01]

Yep, that's how the system knows where you are…

 

[ceric]

Your car has GPS receiver to triangulate where your car is on earth. It needs 4 satellites visible to it. Your SD card has the map. Working together, they can show where your car is on the map. The SD card also contains extra info than map. e.g. speed limits, traffic lights, etc.

 

[BoomerZoomr]

My Mazda navigation shows traffic congestion, even when my phone isn’t in the car. Where is it getting this information from?
edit: plus I get weather alerts.