James Herriot’s books are pretty clean and SFW (like All Creatures Great and Small), but they are also wholesome. They are auto-biographical stories about being a vet in a rural part of north England. He stretches the truth to make a good story, so I would consider them mostly fictional.
Each chapter is relatively stand-alone, which would work with the context of people coming and going - they might get a little slice of the book, but it won’t matter that they weren’t there for the rest of the plot.
It just seems like a good author for the general public.
You could also play popular science books, like those by Bill Bryson (A Short History of Nearly Everything, At Home, and A Walk in the Woods are all great).
Something educational, uplifting, and/or wholesome seems like a good context for the general public, especially public transportation.