Which Are the Longest Highways in the US?

Highways are the arteries of the United States, spanning millions of miles to connect urban centers, rural communities, and natural wonders. The National Highway System includes over 160,000 miles of major roads, while the entire highway network encompasses an astonishing 4.1 million miles. Among these, certain highways stand out for their remarkable length, cutting across multiple time zones, diverse landscapes, and cultural regions. These routes are more than infrastructure; they are stories etched into the geography of a vast nation, reflecting its growth, challenges, and aspirations.

From the dense forests of New England to the sun-soaked deserts of the Southwest, the country’s longest highways weave through 48 states, showcasing the rich tapestry of America’s geography. They connect the agricultural heartland to bustling ports, link historic sites to modern metropolises, and provide vital pathways for commerce, with the trucking industry alone moving goods worth over $10.4 trillion annually across these roads.

In this exploration, we focus on the ten longest highways in the U.S., each exceeding 2,400 miles and offering unique perspectives on the country’s past, present, and future. These highways are more than numbers on a map—they are conduits of exploration, commerce, and connection, embodying the spirit of a nation that thrives on mobility and innovation.

List of the 10 Longest Highways in the US

  • US Route 20 (3,365 miles)
  • US Route 6 (3,207 miles)
  • Interstate 90 (3,102 miles)
  • US Route 30 (3,073 miles)
  • US Route 50 (3,011 miles)
  • Interstate 80 (2,899 miles)
  • US Route 60 (2,670 miles)
  • US Route 2 (2,580 miles)
  • Interstate 40 (2,555 miles)
  • US Route 12 (2,483 miles)

1. US Route 20 (3,365 miles)

At 3,365 miles, US Route 20 holds the distinction of being the longest highway in the United States. Established in 1926, this transcontinental route spans from Boston, Massachusetts, on the Atlantic coast to Newport, Oregon, near the Pacific Ocean.

Traveling along US Route 20 provides a snapshot of America’s heartland and its diverse topography. The route traverses 12 states, including New York, Ohio, Indiana, and Wyoming, crossing major landmarks like Yellowstone National Park. This highway is particularly unique because it skirts historical trails, including parts of the Oregon Trail, reflecting the westward expansion era.

One of the most striking sections is its path through the Midwest’s Great Plains, where long, straight stretches of road seem to touch the horizon. For history enthusiasts, the route provides an opportunity to explore heritage towns and cities like Cleveland, Ohio, and Chicago, Illinois.

2. US Route 6 (3,207 miles)

Commonly referred to as the Grand Army of the Republic Highway, US Route 6 stretches 3,207 miles from Provincetown, Massachusetts, to Bishop, California.

US Route 6 once held the title of the longest highway in the U.S. until it was truncated in California. Even so, it remains a critical artery, especially for connecting New England’s coastal areas to the Midwest and beyond. Its scenic stretches through Pennsylvania’s Allegheny Mountains and Colorado’s Rockies are favorites among road-trippers.

In the eastern portion, the highway meanders through quaint towns, whereas its western end becomes increasingly rugged and remote, capturing the true spirit of American adventure.

3. Interstate 90 (3,102 miles)

The longest interstate highway in the United States, Interstate 90 spans 3,102 miles from Seattle, Washington, to Boston, Massachusetts. Built as part of the Eisenhower Interstate System, this highway is an engineering marvel, connecting major urban centers such as Chicago, Cleveland, and Buffalo.

One of its most iconic sections passes through the Badlands and Black Hills of South Dakota, featuring attractions like Mount Rushmore and Devils Tower National Monument. I-90 is also vital for commerce, linking the industrial Midwest to the agricultural regions of the Great Plains and beyond.

Winters on I-90 can be challenging, especially in states like Montana and Wyoming, where snowfall often leads to hazardous conditions. However, this ruggedness also contributes to the highway’s reputation as a testament to human ingenuity and resilience.

4. US Route 30 (3,073 miles)

Nicknamed the Lincoln Highway, US Route 30 is one of the oldest transcontinental highways in the U.S., stretching 3,073 miles from Astoria, Oregon, to Atlantic City, New Jersey.

As the first road to cross the country coast-to-coast, Route 30 holds historical significance. Today, it runs parallel to several major interstates, serving as a quieter alternative for travelers. In the Midwest, it passes through industrial hubs such as Gary, Indiana, and Toledo, Ohio.

The route is dotted with historical landmarks, including stretches of the original Lincoln Highway. It also skirts farmlands, urban centers, and mountain ranges, offering travelers a comprehensive view of America’s evolving infrastructure.

5. US Route 50 (3,011 miles)

Known as “The Loneliest Road in America”, US Route 50 spans 3,011 miles, connecting Ocean City, Maryland, to Sacramento, California. This nickname is particularly fitting for its section in Nevada, where stretches of road pass through desolate desert landscapes with minimal services.

Route 50’s eastern portions pass through picturesque Appalachian Mountains, rolling hills, and historical cities like Washington, D.C., and Cincinnati. In the west, it dramatically shifts to arid terrain, cutting through Nevada’s Basin and Range Province.

Despite its nickname, the highway is far from empty in terms of natural beauty and historical relevance. It’s a favorite for travelers seeking solitude and a glimpse of America’s untamed wilderness.

6. Interstate 80 (2,899 miles)

Interstate 80 spans 2,899 miles from San Francisco, California, to Teaneck, New Jersey, making it one of the major coast-to-coast highways in the U.S.

As a critical part of the Interstate Highway System, I-80 passes through 11 states and numerous major cities, including Salt Lake City, Omaha, and Chicago. It closely follows the route of the historic Lincoln Highway in many sections, paying homage to its predecessor.

I-80 is vital for cross-country commerce, particularly for freight transport. It also boasts diverse scenery, from the Sierra Nevada Mountains in California to the rolling plains of Iowa and Nebraska.

7. US Route 60 (2,670 miles)

Stretching 2,670 miles, US Route 60 connects Virginia Beach, Virginia, to Brenda, Arizona. It crosses several significant landmarks, such as the Mississippi River and the Ozark Mountains.

This highway is unique in its blend of urban and rural landscapes, passing through bustling cities like Louisville, Kentucky, and quieter regions like the Oklahoma plains. In the Southwest, it transitions to desert terrain, offering striking vistas and access to historical mining towns.

Route 60’s importance lies in its connection of the eastern seaboard to the southwestern U.S., acting as a significant corridor for both travelers and commerce.

8. US Route 2 (2,580 miles)

US Route 2, measuring 2,580 miles, runs from Houlton, Maine, to Everett, Washington, with a northern section that crosses into Canada.

The highway’s route through the northernmost states offers travelers a unique experience. From the dense forests of New England to the vast, open plains of North Dakota and the mountainous terrain of Montana, Route 2 highlights some of the less-traveled but equally mesmerizing parts of the country.

In Washington, the highway concludes near the Pacific Ocean, showcasing the diverse landscapes that make the northern U.S. special.

9. Interstate 40 (2,555 miles)

Interstate 40 spans 2,555 miles, stretching from Barstow, California, to Wilmington, North Carolina. It is a vital east-west corridor, crossing through eight states, including Arizona, Texas, and Tennessee.

I-40 is particularly famous for paralleling much of the historic Route 66, often referred to as the “Mother Road.” This gives travelers a chance to experience modern convenience while reflecting on the past.

The highway’s western portion offers dramatic desert scenery, including landmarks such as the Grand Canyon. In the east, it transitions into rolling hills and urban centers, emphasizing its role as a versatile and essential roadway.

10. US Route 12 (2,483 miles)

At 2,483 miles, US Route 12 connects Detroit, Michigan, to Aberdeen, Washington, crossing several northern states.

Route 12 is rich in historical significance, closely following the path of explorers like Lewis and Clark. It traverses diverse environments, from the urban landscapes of Chicago and Minneapolis to the rugged beauty of the Pacific Northwest.

One of its most notable features is the section through Idaho’s Lolo Pass, offering breathtaking mountain views and access to outdoor recreational opportunities.

Conclusion

These ten highways represent more than just long stretches of pavement—they are lifelines connecting America’s people, culture, and economy. From the desolate beauty of US Route 50 to the bustling corridors of Interstate 80, these highways encapsulate the diversity and resilience of the United States. Whether for commerce, adventure, or history, these routes offer a chance to experience the vastness and variety that define the country.

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