The Pocket PC map software when loaded on the GPS receiver enables users to get to their destination even when they are not familiar with the route. The software that includes street-level maps plots the shortest route to any destination, gives precise, voice guided turn-by-turn directions and even re-routes users when they miss a turn.
The map data and points of interests are licensed to PDA GPS vendors by big map makers who use information provided by government bodies like the county planning agencies. Satellite images and aerial photographs are then integrated with this information along with data obtained from professionals and field staff.
The maps also use inputs from Census Bureau, fire and police departments to provide accurate and comprehensive information. These digital maps are then integrated in the GPS solutions that the Pocket PC makers provide.
The maps used by most automobile GPS systems in the US are made by NavTech, which is one of the biggest map makers. The company has more than 100 field offices which are staffed by trained analysts and engineers who travel hundreds of kilometers every day to map new information about roads. This information is updated every quarter to keep the maps current. This information even includes points like one-way streets and turn restrictions.
Another big map company, which provides US and international map data, is Tele Atlas. It has a large network of field offices that provides extensive information about traffic points. This makes Tele Atlas maps the best source of information for any transport company. They get to know about 350,000 traffic reporting locations across the country from one single map software.
PocketMap City Guide USA that covers more than 100 major US metros and 1,800 cities and towns too provides a comprehensive point of interest business listings database. The company also provides a GPS enabled version for the Pocket PC vendors. Rand McNally, which has been producing printed road atlases for a long time, now also offers a popular digital map package called StreetFinder. These digital city guides incorporate a very extensive point of interest database, which is not available on most other guides.
However, one map that is the source of most maps rarely figures in the map software loaded on Pocket PCs. This is the highly respected Tiger (Topologically Integrated Geographic Encoding and Referencing system) map prepared by Census Bureau. These maps are used not only by the US Government, but also by scores of other map makers.