[p38fln]

We currently have a fairly decent train network for freight - the passenger network sucks in every way imaginable, but as for freight, you can get just about anywhere by train.
There are currently freight services offered by several of the larger carriers (Schneider and JB Hunt for example) that utilize trains as part of their routes. Their trucks pick the freight up at the factory, load it on to the train, then the train takes the freight cross country, where another one of their trucks will unload it and deliver it to the store. This is called 'intermodal' freight, but is limited to freight that isn't time sensitive - trains are nontoriously slow, taking up to a full month to deliver freight during the busiest times of the year. The fastest I ever saw was a full week from Marion, Ohio to Chicago, Illinois - which is less than a day by truck.

As for expanding the electrical network - trucks are some of the most fuel efficient vehicles on the highway, getting about 16.6 g/100 miles to move 22 tons of payload. The average pickup truck gets about 12.5 g/100 miles to move 5 tons (If it's actually being used as a truck).

if enough pickup trucks were used to haul the same amount of payload as one semi-trailer, they would burn 55 gallons per 100 miles traveled (Actually a little more because you wouldn't use half a truck but this is just rough calculations)

A train is more efficient, and would burn about 5.5 gallons of fuel to travel 100 miles with 22 tons of freight (According to BNSF's '1/3 the fuel' estimate).

Railroad - 0.25 g/100 miles per ton of freight
So big trucks - 0.75 g/100 miles per ton of freight
Pickup trucks - 2.5 g/100 miles per ton of freight
4 Passenger car @ 40 MPG with 1000 pound weight carrying capacity
- 5 g/100 miles per ton of 'freight'

I used the 40 MPG figure, based it off of what I remembered about a Toyota Corolla, and didn't take anything off for running at full load. For the pickup truck, I used 8 MPG which is about the worst case scenario, although they can get considerably more with a low profile aero trailer - I got 14 MPG pulling a tractor for example. For the semi, 6 MPG is just about the industry wide average.