The GPS on the market does not have enough resolution to tell you if you are on the road or in the ditch. For example, when the GPS tells you to exit on a highway, but you fail to do it, it takes a while for the GPS to figure out that you are not following the route, because the highway and the the exit ramp are paralel initially and the GPS can not tell which road you are on.
GPS won't help you on this.
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• GPS and GPS are different? maybe... -1800800- ♂ (240 bytes) () 01/18/2009 postreply 10:02:32