The answer to this question, after spending a couple days in the vicinity, is that the library, the park, and the campus (Elmhurst College) across the street are ALL splendid for Pokemon Go - and great locations for Community Day adventuring! Tons of pokestops and lots of gyms, plus beautiful settings with plenty of shade! And liberally strewn benches, too! No need to go anywhere near the train tracks!
I have no idea, but I go there everyday, if you plan on walking around the library to find pokemon not sure how much good pokemon you'd find. As for out and around the library there are train tracks that are quite busy that might have kept pokemon go players from walking around the area looking for pokemon but you're definitely welcome to check it out your self.
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