Senator Ron Wyden et al. are proposing TRIP Bonds
These are basically an allocation of Customs Revenues (making imports more expensive) to the states. Each state gets $1 BILLION dollars (this is a grant program, not loans, the proposal proclaims "the states and localities receive the proceeds as grants."). California just as much as Wyoming (does this sound like a Senate Bill? Not surprisingly co-sponsors are from North Dakota and Alaska (John Hoeven (R-N.D.) and Mark Begich (D-Alaska))).
This of course means the Treasury won't get those Customs Revenues, which means the deficit in Treasury revenue needs to be made up somehow. This is not explained. Further the Treasury loses money on tax credits to Bond purchasers. It looks an elaborate shell game to me.
All this to avoid a Federal Highway Bank where projects actually have to earn their keep and repay the loan, or direct user fees.