Systems and methods that provide map-based directions for mobile devices and other computers are well known. For example, Google Maps for Mobile allows mobile devices, such as cell phones and PDAs, to display maps and text-based directions in response to user requests.
Some software, including Google Maps for Mobile, also allows users to display their progress relative to a map in real time. For example, if a mobile device is able to determine its geographic location, the device may download or otherwise access maps corresponding with its location and then display its location on the map. Mobile devices typically calculate their position via an internal or external GPS component, or by calculating their position relative to one or more cell phone towers.
Relatively complete and accurate maps are available with respect to many parts of the world. However, in many other areas of the world, the map data is incomplete and sometimes even incorrect, particularly when it comes to undeveloped or rapidly-developing areas. For example, a map database may not reflect the fact that a road has been recently built, closed or rerouted. Moreover, the database may be aware that a road is present, but it may not store the street name. Some streets will not even have a name.
One method of coping with the problem of incomplete maps is for mapping companies to retain people who drive around with GPS devices, manually detect road changes and enter new roads into the database. In addition to being relatively expensive, such a method of uploading data to a map database has other disadvantages as well.