I have exactly the same question.
In Canada, the whole country is available in shapefile format that is free of using and distributing (kinda GPL license).
Here’s the license page http://www.geobase.ca/geobase/en/licence.jsp
Here you can download the date http://www.geobase.ca/geobase/en/search.do?produit=nrn&language=en
It would be nice if we could have the whole network. This could boost the number of users from Canada!