Method for providing a preview of a route calculated with a navigation system

摘要

A navigation system uses a geographic database to determine a solution route to a destination and provides detailed maneuvering guidance for following the solution route. In addition, the navigation system includes a preview function that provides a summary of the solution route prior to providing the detailed maneuvering guidance for following the solution route. The preview function is included in the programming of the navigation system. The preview function uses a feature incorporated in the geographic database wherein the portion of the geographic database used by the navigation system when determining a solution route includes references to another portion of the database that includes the actual text of the names of the roads represented thereby. As the navigation system uses the data in the geographic database to determine the solution route, data representing the roads in the solution route are saved, including the references to the other portion of the geographic database that includes the actual text of the names of the roads. After the solution route is determined, the preview function evaluates the data representing the roads in the solution route and provides a list of route preview data structures. The list of route preview data structures includes the references to the portion of the geographic database that includes the actual text of the names of the roads. The list of route preview data structures is used to provide the user of the navigation system with a preview that contains a summary of the solution route. The preview provided to the user can include the names of the roads in the solution route. The names can be obtained from the geographic database using the references contained in the list of route preview data structures. When obtaining the names, the references can be reordered to facilitate accessing the text of the names quickly. By providing a preview of the calculated route, the user is familiarized with the route prior to being given detailed guidance for following the route.