The OSM based German Freizeitkarte also creates very good routable US Topo maps.
They don't specifically mention the US maps on their website but they can be found in this location:
These maps are updated 2-3 times a year I think.
New release (23-03-2016):
There are 7 regions and every map is available as:Code:Please Login or Register to see the links
- GMAP with optional installer
- separate imgages