so you want to move large amounts of people and cargo around? it will be most efficient to build one large specialized engine that pulls a bunch of cheap, modular passenger and cargo compartments in a long line
no they definitely all have to have their own engine
very well, i suppose that increases the modularity. we can have vehicles that carry 50 to 100 people, perhaps, and...
no, we're talking like 5 people, at most, and they have to be very friendly with each other
ugh, fine, so we physically attach them to each other and...
no no no! they can't be physically attached!
coordinate a virtual tether over wifi by having them drive really close to one another?
finally! a technological solution to this problem!