National Tunnel Inventory Element Data

The National Tunnel Inventory Elements dataset was compiled on September 02, 2025 and published on August 26, 2025 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 element data present a breakdown of the condition of each structural and civil element for each tunnel on the National Highway System (NHS). A data dictionary, or other source of attribute information, is accessible at https://doi.org/10.21949/1529051