Interstates (Int.): Controlled access highways that are part of the federal interstate highway system, Locally, they include I-71, I-74, I-75, I-275. Non-Interstates (Non-Int.): Any roadway not part of the federal interstate highway system. National Highway System (NHS): A network of strategic highways, including the interstate highway system and other roadways serving major transport facilities such as airports, ports, and rail or truck terminals.