They had me on "UNNAMED ROAD" far too often,

I don't know a lot about how things work out there, but here state roads get an "SR" number (which is not the same as a numbered state route, but usually is the same number on such roads); Some townships use township road numbers, but not all. There are sometimes unnamed lanes but that's happening less and less as emergency service agencies require names so they can respond to incidents better.

If the road has no name and perhaps even if there is a consistent numbering system, TeleAtlas might not have the data.

Screen-scraping is only sufficient if you can figure out a way to rip DMS or UTM coordinates out somehow, either directly or by calculation.