Why do different computer mapping programs have the same mistakes?
Most companies which produce these programs tend to use the same sources, notably the U.S. Geographic Names Information System ( http://geonames.usgs.gov/ ) and the U.S. Bureau of the Census Tiger/Line® data ( http://www.census.gov/geo/www/tiger/tigermap.html ), primarily because most U.S. government documents have no copyrights. (These companies might also use state DOT documents as data.) Errors persist because companies only sporadically update their products using their sources, and, of course, these updates depend on the original sources being updated. Apr 3, 2005 ——————————————————————————– 15 County highway systems of the U.S. Most U.S. states have road systems maintained by respective counties. These range from fully-signed well-maintained systems with numbering guidelines to minor roads with only internal route designations. Signage varies; many county roads use the pentagon shield as recommended by the National Association
