Buckle Up: The Longest Highways in America

President Dwight D. Eisenhower considered the U.S. Interstate Highway System one of his most important achievements in office, and Americans agree, having dubbed the highway network the "Greatest Public Works Project in History," according to the Federal Highway Administration.

Interstate Highway System: A Safe, Efficient Triumph

At a total of 46,876 miles long, the interstate network is estimated to have cost $128.9 billion to construct, with the federal government footing 90% of the bill. The coast-to-coast surface transportation network has succeeded in making road travel safer and more efficient. The Interstate Highway System is among the safest road systems in the country. More than one-quarter of all vehicle traffic occurs on the interstate, but its fatality rate per 100 million miles traveled is less than half that of all other roadways in the U.S., at 0.55 fatalities per 100 MMT. When the construction of the interstate began in 1956, that rate nationally was 6.05.

Today, not only is the Interstate Highway System essential to American travel, it is one of the nation's most important and dependable means of transporting goods—including foods, sundries, and medical supplies—from state to state.

Stacker compiled a list of the longest interstates in the United States using 2021 data from the Federal Highway Administration. Read on to find out which parts of the nation are part of the lengthiest potential road trip highways and byways.