I’m hoping to be able to improve http://wiki.openstreetmap.org/wiki/United_States_roads_tagging and other pages to remove any inconsistencies. I gess this means first finding them, then probably some sort of vote on whether to go one way, another way, or allow either at the whim of the individual mapper. Would anyone be interested in helping? Or will I get silence, end up changing the pages myself, and get reverted? 
Well I would, but I’m not sure how much value I could add as I live in the UK!
I did read the talk page on Motorways, though. I didn’t realise that this was a term used in the states. In the UK, Motorways have a specific legal definition and you can see some of the restrictions at Wikipedia on the “Motorway ahead” sign http://en.wikipedia.org/wiki/Motorway
Do these define a “motorway”? Don’t know.