Hey Brad, This is from someone of your ClariNet days now transported to the midwest. What a bizarre coincidence that I just happen upon your post of GPS map making from user data. Several times at ClariNet we stumbled on the same idea. If you check my web page you might get the clue that I do a lot of navigating with GPS and real-time navigating on my laptop, plus handheld. And I do this where map data is old and often wrong (who cares, except we crazy geodashers, about a random place in Kansas where a bridge is out). Anyway I have long been interested in a colloborative project for not only collecting tracklogs for mapping, but ideally even close enough to real-time to do things like detect construction delays or road closures and such. Obviously a baseline of unimpeded data could generate an average speed, per time of day, per day of week, for stretches of road, so that even just a few tracklogs showing a one or two sigma deviation would indicate a likely problem. As to mapping itself I had done a personal project just to determine if in fact anyone knows exactly where interstate highways are. Now, if that isn't known (and it isn't, precisely or widely) then imagine how hard it is to get data on county roads in South Dakota. Anyway if you're really into this, drop me a line as I might not happen back here.

The other neat thing to consider, given how WAAS was retrofitted into earlier GPS standard, is that satellite broadcasting of critical driving info (weather, road status) in burst mode for the entire of north america, repeated with any updates on continuous basis, can be picked out by the GPSr that definitely knows where you are, but also with a programmed route knows where you're going and so therefore the relevant data from the broadcast can be buffered up and then displayed to the traveler. Here in the midwest where weather can change by the minute and by the mile and be life-threatening, all the existing information channels are hopelessly inadequate. The world is so biased toward point-to-point, on-demand info (sorry, the net isn't going to reach nowhere South Dakota any time soon and that's where this is needed) that broadcast gets ignored, but somehow people need to put GPS and filtering broadcast in the same idea and they might see a whole great new opportunity.

Actually there are a number of ideas one quickly gets when one drives about 10,000 miles in the middle of nowhere looking for random places.

douq millar (variation on the real one)