Systems and methods for determining an improved user location using real world map data and/or sensor data are provided. In one embodiment, the method can include obtaining an initial estimate of a location of a user device and maps information corresponding to a geographic area at least partially surrounding the initial estimate of the location of the user device. The maps information can include one or more physical boundaries located at least in part within the geographic area at least partially surrounding the initial estimate. The method can further include determining a set of permissible areas that can potentially include the user device. The set of permissible areas can be determined based at least in part on the one or more physical boundaries. The method can further include revising the initial estimate to provide a revised estimate for the location of the user device based at least in part on the set of permissible areas.