It's not impossible, a lot of good Sci-fi is derivative. But Ringworld, as you've stated, doesn't really take anything more than the setting, a giant ring, I've not read Destiny's Road but what I can glean from google seems to suggest that the only links here are the title and the circular city. It could just be a coincidence, or Bungie paying tribute to one of the most influential people in Sci-fi. Perhaps Jason Jones is a fan?