Components
The NHS consists mostly of existing two-lane roads. About 98% of all roads in NHS have been built. The 160,000 miles of NHS include only 4% of the nation's roads, but they carry more than 40% of all highway traffic, 75% of heavy truck traffic, and 90% of tourist traffic. About 90% of America's population lives within 5 miles of an NHS road. All urban areas with a population of more than 50,000 and 93% with a population of between 5,000 and 50,000 are within 5 miles of an NHS road. Counties that contain NHS highways also host 99% of all jobs in the nation, including 99% of manufacturing jobs, 97% of mining jobs, and 93% of agricultural jobs.

History and justification

Interstate Highway System
Strategic Highway Network
United States Numbered Highways
Federal Highway Administration
Adopt a Highway