1. A method for testing data defining one or more navigation routes, the method comprising: inputting at a computer one or more starting locations remote from a location of the computer; inputting at the computer one or more destination locations; receiving at the computer map data including GPS information for one or more geographical vicinities based on the starting location input and the destination location input; receiving at the computer route data; using the computer to generate data defining one or more navigation instructions for one or more routes based on the map data and the route data; executing at the computer the one or more navigation instructions for testing the navigation instruction data; comparing the executed navigation instructions to the map data; determining an accuracy of the navigation instructions based on the comparison; and correcting the data defining navigation instructions if the data is determined to be inaccurate.