JF Ptak Science Books Daily Dosage from Dr. Odd 1
This remarkable cutaway (1910) shows what might have been considered a possible future for the future of possible New York Citys . This one features a very highly respectful continuous conveyor belt of humanity coursing through the Great Underneath, replacing the ideas of subway transport. A seat would always be available if it was so, just a=one giant beltwork of seat stretching from SOuth Ferry to Uptown and to Brooklyn and so on. But since it was always moving it would have to move a little slowly for people to hop on and off, so a trip to the then-Uptown might take some time.
Source: New York Public Library Digital Collection, here.
Not to be out-belted, there was also an image of moving sidewalks (1903):
Source: New York Public Library Digital Collection, here.