>>1424395>vacuum tube trainsThat is a possibility, but not always more efficient as you need an air supply in the train and you need to repeatedly evacuate the stations.
The advantages for the enviroment are neglectable anyway, so it isn't worth the huge extra effort.
Building a decent rail network, not even highspeed, is a huge project even on a national scale.
IMHO 150-200 km/h is a reasonable speed for regional/intercity trains as that allows for reasonably fast and efficient travel with conventional trains.
Only long distance trains with rather few stops would realy benefit from higher speeds.
>why not just use another underground train that isn't meant for passengers but only for moving cargo from city to city?That was basicly my idea, just that the electric cargo vehicles transport the cargo from its origin to the trainstation, the train takes it to the destination city where another electric cargo vehicle picks it up and travels to the destination.
>moving cargo within the city can be done with pic related but bigger.At the point where you reach a usefull scale you need more than just human power to move at more than walking pace.
Just think about moving 200 kg of potatos, 100 kg of apples and 300 kg of strawberries from a farm to a market with these things, that would be a nightmare.