What constitutes a Federal off-system bridge or road?
Any bridge or road not on the National Highway System is considered to be off-system from the standpoint of Federal aid. The National Highway System is “approximately 160,000 miles of highways important to the nation's economy, defense, and mobility.” The National Highway System includes all of the Interstates and many principal major arterials connecting major cities, border crossings, transportation facilities such as ports and airports, and designated military installations.
To see which roads in your area are on the National Highway System, you can use the resources below.
Resources
National Highway Map Viewer (Best viewed in Internet Explorer)
Highway Systems - Federal-Aid Policy Guide
March 2012