there are 472 New York subway stations, and one man has been sketching them since 1978, and he's not done yet, in fact, he's only done 110... very detailed, and it's roughly 3 notebooks per station. 41 so far

A selection of Coppola’s work has just been published under the title “One-Track Mind.” Now seventy, he hopes to complete all four hundred and seventy-two stations by the mid-twenty-thirties. “My goal is to get the whole thing done before I go,” he said.

One-Track Mind is a diminutive selection presented in a single neat and tidy 5x7 package. It begins with a section of Coppola’s hand drawn maps of the subways transit layout for Contract 1 (1905 Manhattan-Bronx line) and Contract 2 (1908 Brooklyn line) and ends with reproductions of a few original journal pages. In between are station drawings that range from full elevations and rooflines, to tiny railing designs, name panels, pilasters, corbels, fixtures, and more.

https://www.newyorker.com/magazine/2018/05/07/sketching-the-mta-with-a-subway-archeologist

At six self-published volumes, and two thousand pages, “Silver Connections” was an exhaustive visual history of the underground transit system that was published in 1984 and with only 900 copies, and isn't available anywhere anymore.

Inside are Coppola’s ink sketches, with notes, of a hundred and ten stations, including meticulous keys to indicate the color of every tile.

https://www.nyjournalofbooks.com/book-review/one-track-mind
https://books.google.com/books/about/One_Track_Mind.html?id=hMNZDwAAQBAJ&printsec=frontcover&source=kp_read_button#v=onepage&q&f=false