National Highway System (United States) - Overview

Overview

The 160,000-mile (260,000 km) National Highway System includes roads from one or more of the following road networks:

• The Interstate Highway System
• The Strategic Highway Network (STRAHNET) of importance to the United States' strategic defense policy including links from major military installations and this Strategic Highway Network
• Access to 207 airports, 198 ports, 190 rail or truck terminals, 67 Amtrak railway stations, 58 pipeline terminals as well as 82 intercity bus terminals, 307 public transit stations, 37 ferry terminals and 20 multi-purpose passenger terminals

The system includes 4% of the nation's roads, but carries more than 40% of all highway traffic, 75% of heavy truck traffic, and 90% of tourist traffic. All urban areas with a population of over 50,000 and about 90% of America's population live within 5 miles (8.0 km) of the network, which is the longest in the world.