We all know L.A. is a car-first city, but the numbers are still surprising. A recent study took a closer look at the most congested roads in the country, and the city dominated the list, confirming just how extreme traffic has become across the region.
According to data from the Federal Highway Administration (FHWA), a stretch of Interstate 5 in Los Angeles sees about 504,000 vehicles per day, more than any other highway in the country. And it’s not an outlier, as several other L.A. freeways also rank among the most congested nationwide.
Why does L.A. dominate the list of the busiest highways?
California leads the ranking of the busiest highways in the U.S., with 12 of the top 25, and Los Angeles is the main reason for this. The city’s layout depends heavily on cars, with long commutes, limited public transit options, and millions of residents sharing the same freeway system.
Add nearly 50 million yearly visitors, and congestion becomes unavoidable. According to FHWA data, these are the highways with the highest daily traffic volumes:
- CA I-5 — Los Angeles–Long Beach–Santa Ana, CA — 504,000
- GA I-75 — Atlanta, GA — 419,516
- CA I-5 — Mission Viejo, CA — 415,000
- CA I-405 — Los Angeles–Long Beach–Santa Ana, CA — 383,500
- TX I-10 — Houston, TX — 313,693
- TX I-10 — Houston, TX — 312,068
- TX I-10 — Houston, TX — 273,454
- CA I-210 — Los Angeles–Long Beach–Santa Ana, CA — 358,000
- CA I-10 — Los Angeles–Long Beach–Santa Ana, CA — 355,000
- CA CA-60 — Los Angeles–Long Beach–Santa Ana, CA — 350,000
Study methodology
This FHWA uses a metric called Annual Average Daily Traffic (AADT), which measures how many vehicles use a road each day on average over the course of a year. It’s one of the most widely used ways to compare traffic levels across highways.
Additional context on congestion and driving conditions comes from travel guides, mapping tools like Google Maps and Waze, and user-reported experiences on forums.
