It would be possible in a diesel at some complexity. "COST" This problem is what prompted MPC to develop the fast angle wheel for rolling stock. Even real railroads use a tapered tread on car wheels and the head of the rail is not perfectly flat so the truck rides to the outside of the curve putting the fat larger diameter inside section of the tread on the outside rail and the smaller diameter outside of the tread aligns for the inner rail.
I could see a fast spinning axle with magnets spinning on each end inside a cup behind each wheel. The wheels would spin free on the axle propelled by the eddy currents of the spinning magnets "eddy current clutch". Allowing differential between the inside and outside wheel. WHEW ! You would need a 48 month loan the pay for your next Plymouth switcher.
Kidding aside, Eddy Current Clutches are quite effective in model train drives allowing for very smooth low speed operation. j
