I'll bet IF the FedGov and various states pitched the idea to the trucking industry of *truck only* tollways with no passenger vehicles (aside from cops) that had reasonable fees - they'd jump on it. Higher speed limits, no "4 wheeler" traffic to deal with. They could go further each day, theoretically.
The passenger vehicles staying on their road, separate from the trucks would theoretically be safer because they're not interacting with large numbers of commercial vehicles moving slower (and the differential in speed is more dangerous than the size and presence of the commercial trucks)
Everyone should be happier and safer.
And because that makes sense, it'll never happen.
Kinda like what the railroads had before the government ended up subsidizing their competitors, the trucking companies, with Ike’s creation of the interstate highway system.