The subway has some great efficiency gains because it's use is so narrow. It can only transport humans and small amounts of luggage, and only goes from point to point with no variability or any real use for transporting any of the materials those people need to survive. You're just dumping the costs off to other areas.
Also, if you factor in the construction, idk what the timeline to pay that off would be.
ok, so then you should also factor in the environmental destruction cause by building roads, the cost of the roads, the environmental cost of burning petrol, the environmental damage of extracting and refining petroleum, and so on.
I thought the comparison was to a BEV, not ICE.