1. A computer-implemented method for refining mapping data, the method comprising: receiving, at a server, input location coordinates of a mobile device, wherein the server is configured to host a memory storing mapping data, the input location coordinates corresponding to a plurality of location coordinates associated with a sequence of locations along which the mobile device has previously traveled; identifying one or more candidate routes based on the input location coordinates of the mobile device; comparing the one or more candidate routes to known paths in mapping data previously stored in the memory hosted by the server; using a processor at the server to: calculate a route score for each candidate route based on the comparison, select, based on the route score, a route that was most likely previously traveled by the mobile device based on the sequence of locations associated with the input location coordinates, and identify a transition segment in the route that was most likely previously traveled by the mobile device as a missing path of the previously stored mapping data, wherein the transition segment links one location coordinate to a next location coordinate that is not along an existing path previously stored in the mapping data; and adding the missing path to the mapping data stored in the memory hosted by the server.