That’s extremely realistic. The Netherlands has a separate system for bikes. The truck system would just be what the motorized traffic system is now, be it a bit scaled down.
The interstate system and truck delivery seems to be pretty fantastic at servicing the continental US when paired with freight trains, cargo planes, etc. And it is similarly effective for delivery of all other kinds of things including people.
These systems would be good to implement in many cities, but interstate shipping and travel is another thing altogether.