How is the road in the first paragraph used as a metaphor in Invisible Man

The seemingly bucolic description of the narrator's "beautiful college" which begins the chapter is deceptive as Ellison throws in negative images to upset the balance and shadow the story with a darker foreboding sense. His tone is ironic as he mentions the path that turns off to the insane asylum or how "boys in the know" were given special treats by the gay nurses. His pure campus was truly anything but that. The bastion of equality through intellect was a metaphor for more sinister things.