Infrastructure

This Is the Longest Road in America

The national road and highway system in America was a patchwork for decades. That changed with the passage of the Federal-Aid Highway Act of 1956. Today, it is widely known as the Dwight D. Eisenhower National System of Interstate and Defense Highways. It created common standards for the highways in the system, the first time this happened in American history. The system includes highways that, in total, cover almost 45,000 miles.

Oddly, the longest highway in the country is not part of the interstate system. Its designation comes from the older naming convention of U.S. highways. U.S. Route 20 is the longest highway in the country at 3,365 miles, according to the Department of Transportation:

The route begins in Boston at a junction with Massachusetts Route 2 and ends in Newport, Oregon, at a junction with U.S. 101. Because U.S. numbered highways are not designated with National Parks, U.S. 20 is divided into an East Section ending at the eastern entrance to Yellowstone National Park and a West Section beginning at the west entrance to the park.


U.S. 20 runs through 12 states: Oregon, Idaho, Montana, Wyoming, Nebraska, Iowa, Illinois, Indiana, Ohio, Pennsylvania, New York and Massachusetts. These states are responsible for maintaining and repairing the road.

U.S. 20 is famous with many drivers. The Historic US Route 20 Association, a nonprofit organization, maintains detailed histories of the route, follows and posts media coverage, creates and sends a newsletter, and even has a store.

U.S. 20 is one among 10 highways that run over 2,400 miles each, according to EZ Freight Factoring. Some of these carry the U.S. highway designation. Others are part of the interstate system. The longest of these, I-90, covers 3,102 miles

These are the 10 longest highways in America:

  • U.S. Route 20 (3,237 miles)
  • U.S. Route 6 (3,207 miles)
  • I-90 (3,102 miles)
  • U.S. Route 30 (3,073 miles)
  • U.S. Route 50 (3,011 miles)
  • I-80 (2,899 miles)
  • U.S. Route 60 (2,670 miles)
  • U.S. Route 2 (2,580 miles)
  • I-40 (2,555 miles)
  • U.S. Route 12 (2,483 miles)

Click here to read about states with the most dangerous roads.