HIFLD OPEN National Tunnel Inventory

The National Tunnel Inventory dataset was compiled on July 22, 2024 and published on July 24, 2024 from the Federal Highway Administration (FHWA) and is part of the U.S. Department of Transportation (USDOT)/Bureau of Transportation Statistics (BTS) National Transportation Atlas Database (NTAD). The National Tunnel Inventory (NTI) is a collection of information (database) describing the more than 500 of the Nation's tunnels located on public roads, including Interstate Highways, U.S. highways, State and county roads, as well as publicly-accessible tunnels on Federal lands. The inventory data present a complete picture of the location, description, and classification data for each tunnel, as well as any load rating and inspection information. The element data present a breakdown of the condition of each structural and civil element for each tunnel on the National Highway System (NHS). The Specifications for the National Tunnel Inventory (SNTI) contains a detailed description of each data element including coding instructions and attribute definitions. The Coding Manual is published for each year of data collection.