Are trains more energy efficient than cars for human transport, basically, which form of transport consumes more watts per km per passenger? Passenger trains certainly have a lot more weight per passenger especially when not fully loaded than cars but on the other hand from what i've heard those big diesel engines are really efficient compared to smaller ones found on cars.
And why do passenger train cars even have to be so goddamn heavy when they aren't transporting anything heavy?
I mean surely they would save a lot of fuel, ie. money, from not having to try and accelerate passenger cars that weigh more than a tank to 100km/h, is there any reason for a passenger car to weigh more than your usual bus?