7 of the busiest highways in America — and 1 of the loneliest

If you are on I-5 in the Los Angeles area and think that it can’t get much busier: You are correct. With an Annual Average Daily Traffic (AADT) of over a half-million (504,000), this qualifies as the busiest highway in the USA.

Valvoline (VVV) surveyed 1,000 Americans, and the results showed that The Great American Road Trip is back, with road trips expected to hit a 20-year high this Memorial Day weekend.

Valvoline data also showed that airline mishaps are also pushing younger travelers to drive instead, with 35% of Gen Z saying the economy strongly influenced their decision to hit the road, compared to just 11% of Boomers.

Gas prices are also a key factor for 27% of Gen Z and 24% of Millennials.
 

Atlanta traffic ranks among the worst with 419,515 AADT. Many families transiting too and from the Upper Midwest to Florida try to plan their drives through Atlanta during the middle of the night. Or somehow avoid it altogether. But that is tough with Atlanta’s prime perch right on I-75.

Mission Viejo may not be what you think of when you hear about busy highways. Places like Chicago or Boston or Philly may come to mind, but I-5 through Mission Viejo sees 415,000 cars per day on average, making it good for third place.

“As the summer driving season kicks off, some of the busiest highways in the United States are expected to see even heavier traffic. California’s I-5 through Los Angeles holds the title as the nation’s busiest highway, with over half a million vehicle trips daily, which will likely see a surge in traffic this summer,” noted Maddie Bourgerie, travel expert at RVshare.

Several stretches of I-10 through Houston are enough to give drivers indigestion every day, with several stretches seeing well over 300,000 cars a day.

“Texas features one of the country’s busiest highways,” Bourgerie said, adding that this surge in highway activity coincides with a record-breaking travel season. Bourgerie also said I-35 from Dallas–Fort Worth to San Antonio is one of the South’s most trafficked roads.

Everyone is itching to get the beach — or work — and that creates a congested combination day in and day out in Miami with over 330,000 cars a on a stretch of I-75.

“Travel behavior is changing, as people are becoming more economically cautious. Tariffs, economic uncertainty, and inflation — all the factors trickle down into travel sentiment,” noted Mercedes Zach, travel expert at ASAPtickets.

“To save additionally, one might even choose to drive instead of booking a flight — cheaper gas makes road trips more attractive, while higher airfares, specifically for domestic flights, are causing people to rethink their travel plans,” Zach said, adding that flights that used to be $99 just a decade ago are now priced at $400–$500, even on competitive routes like LA to New York.

“The U.S. airline market has consolidated a lot over the years, and with fewer major players, there’s less downward pressure on prices,” Zach added.

With over 332,000 cars a day, I-15 in Las Vegas is full of cars and perhaps some slot machine winnings. But odds are, you’ll be stuck in traffic.

I-90 through Chicago can be the stuff of traffic nightmares, and that is because more than 320,000 cars a day traverse this stretch of highway.

A survey by Pilot fuel centers and Campspot reveals that Americans are leaning into short, spontaneous road trips under 200 miles, dubbed “Pop-Up Escapes.” Key takeaways:

90% say they’re interested in 1–3 night getaways
57% say under 200 miles is their ideal trip distance
76% plan to spend less than $500
Top priorities: scenic routes, hidden gems, and 24/7 accessible stops

If scenic routes are your priority, you’ll steer clear of Chicago traffic!

If you want to get away from it all, try the Dalton Highway in Alaska where, according to Frommer’s, only 250 vehicles a day traverse its entire 500 mile length.

“This is an extreme road trip, one that dives into deep wilderness as far from help as most people ever get. In 500 miles there are only three service stations, two of which are within 4 miles of each other,” Frommer’s notes.