Comment by hasmanean

Yeah, efficiency for a train means cargo divided by the cost of the driver and the costs of the locomotive.

Take the driver out of the equation, and suddenly making the train longer doesn’t provide any savings. You might as well switch to smaller and cheaper engines and divide one train into 10.

There are a lot of variables that affect efficiency but new technology alters the landscape. Self driving public transit is one such thing. Would you rather be on a bus with one driver or a self driving taxi that costs the same?