Vactrains already existed as a concept when these were produced, though I don't see anything that looks _particularly_ like one? All the mass transit I can see in the pictures looks like suspension monorails (like https://en.wikipedia.org/wiki/Wuppertal_Schwebebahn, which was built some years prior to these pictures).
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One of the pictures reminded me of Elon Musk and his Hyperloop.
Vactrains already existed as a concept when these were produced, though I don't see anything that looks _particularly_ like one? All the mass transit I can see in the pictures looks like suspension monorails (like https://en.wikipedia.org/wiki/Wuppertal_Schwebebahn, which was built some years prior to these pictures).