America's Most Congested Cities

Forbes has released its list of the most congested cities in America. Los Angeles, New York, Chicago, Dallas and Washington D.C. top the list.

1 minute read

March 3, 2009, 6:00 AM PST

By Nate Berg


"To determine America's Most Congested Cities, Inrix collects data from nearly 800,000 anonymous, GPS-equipped commercial vehicles that report their speed and location continually to Inrix. The company then processes and blends other relevant traffic-related data such as road sensors, toll tags, traffic-incident data and other resources to figure out when, why and for how long particular roads experience bottlenecking."

"The worst hour for travel in Los Angeles, on average, is Thursday at 5 p.m. In New York, the second-worst city for congestion in the country, it's Friday at 5 p.m. Like L.A., Chicago and Washington are at their worst on Thursdays at 5 p.m., while Dallas, like New York, is most congested on Fridays at 5 p.m."

"But the devil really isn't in the details; it's unsurprising that these cities come out on top when it comes to congestion. The top four spots on the list also have the largest populations in the country: Los Angeles--12.9 million; New York--18.8 million; Chicago--9.5 million; and Dallas--6.2 million."

"What is surprising, however, is that every single city on our list of 20 saw a decrease in congestion over the 2008 calendar year. Some of the cities with the largest decreases in traffic include Riverside, Calif.--which saw congestion drop by 57% --and Detroit, where congestion was whittled by 47%."

Thursday, February 26, 2009 in Forbes

portrait of professional woman

I love the variety of courses, many practical, and all richly illustrated. They have inspired many ideas that I've applied in practice, and in my own teaching. Mary G., Urban Planner

I love the variety of courses, many practical, and all richly illustrated. They have inspired many ideas that I've applied in practice, and in my own teaching.

Mary G., Urban Planner

Cover CM Credits, Earn Certificates, Push Your Career Forward

Aerial view of town of Wailuku in Maui, Hawaii with mountains in background against cloudy sunset sky.

Maui's Vacation Rental Debate Turns Ugly

Verbal attacks, misinformation campaigns and fistfights plague a high-stakes debate to convert thousands of vacation rentals into long-term housing.

July 1, 2025 - Honolulu Civil Beat

Logo for Planetizen Federal Action Tracker with black and white image of U.S. Capitol with water ripple overlay.

Planetizen Federal Action Tracker

A weekly monitor of how Trump’s orders and actions are impacting planners and planning in America.

July 9, 2025 - Diana Ionescu

Map of Haussmann's redesign of Paris in the 1850s through 1870s under Napoleon III.

In Urban Planning, AI Prompting Could be the New Design Thinking

Creativity has long been key to great urban design. What if we see AI as our new creative partner?

June 30, 2025 - Tom Sanchez

View of dense apartment buildings on Seattle waterfront with high-rise buildings in background.

King County Supportive Housing Program Offers Hope for Unhoused Residents

The county is taking a ‘Housing First’ approach that prioritizes getting people into housing, then offering wraparound supportive services.

July 11 - Real Change

Aerial view of suburban housing near Las Vegas, Nevada.

Researchers Use AI to Get Clearer Picture of US Housing

Analysts are using artificial intelligence to supercharge their research by allowing them to comb through data faster. Though these AI tools can be error prone, they save time and housing researchers are optimistic about the future.

July 11 - Shelterforce Magazine

Green bike share bikes parked in a row on a commercial street with outdoor dining and greenery.

Making Shared Micromobility More Inclusive

Cities and shared mobility system operators can do more to include people with disabilities in planning and operations, per a new report.

July 11 - Cities Today