As of an update to the map situation, after spending lot of time investigating with the USGS vector maps, I can't figure out the direction of one-way roads. Also, there's the additional problem of merging the Tiger and USGS maps together with the position inaccuracies.

However, I've recently found one possible source of map data which is designed for car navigation and the maps are available for both US and Europe. But I need to investigate further before I can tell more.

I'm also interested to hear more about the NavTech maps, so feel free to find out some details and let us know!

Kim