Now I'm wondering: A +/- 167feet accuracy (about 51 meters) isn't even as good as GPS is. And around my house, 167feet is surely more than the space between two parallel streets.

True, this could be a problem. Though, it would be interesting to see whether this means more like a constant offset or a varying +/- 50m error in the coordinates. This is one reason why I was asking for a GPS log data so that this could be verified.

I guess this could be corrected with the aid of the user (like the CityMaps and RoutePlanner apps from www.palmtop.nl are doing it), but how often would that be needed on long distance drives?

I don't know how the software works that you refer, but I'd think that the error won't grow over distance. I mean, it's not relative to any particular source position.

I am still trying to find out how much efford (money and contract wise) it would be to license the TeleAtlas data format.

TeleAtlas has one internal data format (called MultiNet) from where they produce maps for different navigation hardware vendors. All navigation disks that they sell are in vendor specific format (i.e. Audi, Blaupunkt, Mercedes, Mannesman/VDO) and I believe that those are proprietary formats and maybe even TeleAtlas won't have the right to give out the specs. But, as far as I know, the MultiNet data is in GDF format for which the specs should be freely available. They are also selling the MultiNet data but the question is how expensive that is. Maybe you could figure it out? TeleAtlas has an office in Germany, also.

If I could collect some GPS positions of street interconnections, along with information about those streets (like direction, speed limit, name), would that be enough information for you to create a suitable map? If so, I would be willing to collect that information for the area of the next owners meet (about a square kilometere or two), so that your application could be demonstrated there.

The data that I now have includes street name, road class, street numbers, one-way/two-way info, city name, zip code and a list of coordinates per road. That suffices for quite long. But how were you thinking to gather the data, somehow manually?

Kim