1. A system for providing a geographic database comprising: a plurality of sensors, each of said sensors installed in a separate one of a plurality of vehicles each of which is capable of traveling on roads in a geographic region, and each of said sensors being operative to provide outputs indicative of physical features sensed by said sensor in said geographic region as its respective vehicle travels on the roads in the geographic region; a geographic database including data representing the features in the geographic region, and including data identifying attributes of said physical features; an updating feedback program comprised of a first program portion that compares said outputs to said data identifying the physical features and provides results representative of said comparisons; a second program portion responsive to said results from said first program portion to determine a measure of significance taking into account a number of said outputs; and a third program portion operative to modify said data identifying the physical feature based upon said measure of significance determined by said second program portion.