That would leave the present Interstates for passenger vehicle use only -- which would increase safety, decrease IH traffic volume, and extend the infrastructure's usable lifetimes tremendously.
That would be fantastic but wouldn't the trucking industry go nuts and moan about road/fuel taxes etc. while ignoring the damage their vehicles cause daily?
Well actually if the road beds were constructed the same way the Germans built their Autobahns, the roads would last 50+ years before needing any major repair as opposed to the every 12 to 20 years here in the U.S.
The road beds and the wearing surface of the Autobahn is twice that of whats found on our interstates here in the U.S. and thus are less susceptible to damage due to freeze/thaw cycles, settling, and premature wear.