I probably should have qualified the electric comment as applying to N.America. The size of the Class 1 railroads and the distance covered by run-through diesels pretty much elimintates the electric idea unless it's applied to large amounts of the railroad (prohibitively expensive). Also, we have few main lines with the traffic density to make electrics interesting for operational reasons (more power per unit) outside of high-volume passenger lines (NEC & commuter).

UP has published a map showing where a typical mainline locomotive can go in a month, just within their system. It's eye-opening - covers over 1/3 of the U.S.