If you’re a fan of road trips, you’ve probably passed through different highways of different lengths. Sometimes, traveling by car can take just a few hours, while other times, it can take up a whole day. While driving down the highway waiting for traffic to move, you’ve probably wondered to yourself, “what is the longest highway in the United States?”
Whether you’re going on a road trip or simply curious, this guide got you covered! Sit back, put your seatbelt on, and learn all about interstate and U.S. highways while we answer the question, “what is the longest highway in the U.S.?”
What is a highway?
Before we can answer the question, “what is the longest highway in the United States?”, it’s important to first understand what a highway actually is.
It might seem obvious, but people often use “highway” and “freeway” interchangeably. While the two are certainly related, they are not the same thing. A highway is the main road that connects towns, cities, and even states.
Meanwhile, a freeway is also a main road that cars can only access through ramps. The ramps separate freeways from other roads and traffic, which allows vehicles to move faster on freeways. Because of this, a freeway is also called an “express highway” or a “controlled-access highway”.
To put it simply, all freeways are highways, but not all highways are freeways.
How are highways named?
If you travel regularly by car, then you’ve probably already noticed how highways have numbers in their names. Contrary to popular belief, these numbers aren’t randomly assigned. These numbers actually have specific meanings.
The names of interstate highways have the format of Interstate X.
Interstate highways refer to highways that cross state boundaries to connect all 48 U.S. states. These highways belong to the Interstate Highway System. Its name is a combination of the letter “I” and one to three-digit numbers.
Highways with one or two digits in their names are primary interstate highways. Meanwhile, those with three digits in their names are auxiliary interstate highways. Interstate highways with odd numbers connect south to north, while those with even numbers connect west to east.
Meanwhile, the names of U.S. highways have the format of U.S. Highway nn or U.S. Route nn.
U.S. highways, or U.S. routes, belong to the United States Numbered Highway System. Like interstate highways, U.S. highways connect different states. However, most motorists use U.S. highways to travel from one local or regional destination to another.