Of course interstate shipments can always go back to using trains instead of a daisytrain of trucks all going the same route for several states.
They have been doing this to an increasing extent since the 1930s and especially the 1980s. It is called intermodal or stack trains. Changes in transport design have resulted in very few factories or warehouses having rail access.
Unfortunately due to turnaround times the Railroads are not interested in less than unit train shipments that travel less than 500 to 750 miles. Once you tack on the shift to load and unload the well cars at each end of the trip it is quicker dock to dock to just use a truck. Also you would still need a truck to get the container from the dock to the intermodal yard at the start and from the intermodal yard to the destination.
Of course interstate shipments can always go back to using trains instead of a daisytrain of trucks all going the same route for several states.
There will be driverless big rigs fairly soon. They will be great for cross country long hauls. Schedule them to run on the interstates, say midnight to 5:00am, put them in the inside lane and let them rip...