The glass corridor at the Derry Public Library connects the adult library to the Children’s Library. In the novel, the glass corridor represents the passage from childhood to adulthood. King based the corridor on an actual one at the Stratford Public Library in Connecticut, which connects the children’s library to the adult library.
As a child, Ben Hanscom, a frequent visitor to the library, notices how the corridor is warm, even in winter. The corridor is designed to ease one’s passage, and symbolically this means doing so in the transition from one phase of life to another. It is a source of comfort for Ben, who replicates its design when he becomes an architect and constructs the BBC communications center in London. Both during childhood and in adulthood, when he returns to Derry, he overhears a librarian reading the Norwegian fairy tale, “Three Billy Goats Gruff” to a group of children. Hearing the story returns Ben to his childhood feeling of being an overweight and bullied social outcast. The Derry Public Library has always been Ben’s sanctuary, but there were terrors lurking outside of its walls that threatened to disrupt Ben’s passage from boyhood to manhood, particularly It and Henry Bowers.
At the end of the novel, the glass corridor explodes. The bridge is never rebuilt and patrons have to go outside to get from the Children’s Library to the adult library. The bridge’s collapse is symbolic of Ben’s break away from the terrors that haunted him in childhood.