PASSIVE CROWD-SOURCED MAP UPDATES AND ALTERNATE ROUTE RECOMMENDATIONS

Systems and methods for providing passive crowd-sourced alternate route recommendations. In one embodiment, locations of users of a number of mobile location-aware devices are tracked over time. Upon receiving a request, users of mobile location-aware devices that have traveled from a desired start location to a desired stop location are identified. Location histories for the identified users are analyzed to determine one or more different routes taken from the desired start location to the desired stop location. The one or more different routes, or a select subset thereof, are then returned to the requestor as recommended alternate routes.