The two cities are home to eight of the nation's top 10 most congested corridors, according to a new study by traffic research firm Inrix. The company released its annual scorecard Tuesday, measuring gridlock in the largest U.S. cities.
A 13-mile stretch of I-405 west of downtown Los Angeles ranked as the most congested corridor, with average delays of 20 minutes in 2011.
Backups are an everyday occurrence on many roadways in sprawling metropolitan areas. The average speed last year was only 14 mph for a portion of the Van Wyck Expressway in New York. Similarly, a stretch of Interstate 379 west of Pittsburgh clocked in with an average speed of just 16 mph.
The firm also scored cities, finding traffic congestion actually dropped in most cities in 2011 after increasing the previous two years. The company attributed the reduction to fewer vehicles clogging roadways because of higher gas prices and a "largely jobless economy."
Honolulu was dubbed the metropolitan area with the nation's worst traffic, with drivers spending an estimated 58 hours in traffic over the course of the year. Los Angeles, San Francisco and New York City had the next-worst traffic, according to the study.
Inrix compiled traffic data from more than 100 million vehicles equipped with GPS devices tracking motorists' location, speed, direction and time.
The firm ranked the worst corridors, shown below, by multiplying the average delay by a separate index measuring the longest commute times during peak periods.
| City | Miles | Roadway | Average Time (minutes) | Delay (minutes) |
|---|---|---|---|---|
| Los Angeles | 13.1 | I-405 Northbound: I-105/Imperial Hwy interchange to Getty Center Dr. | 33 | 20 |
| New York | 16 | Long Island Expressway Eastbound: Maurice Avenue to Minneola/Willis Avenues | 39 | 22 |
| Los Angeles | 14.9 | I-10 Eastbound: CA-1/Lincoln Blvd. to Alameda Street | 35 | 20 |
| New York | 3.1 | Van Wyck Expressway Northbound: Belt Parkway to Main Street, exit 8 | 13 | 10 |
| Los Angeles | 17.5 | I-5 Southbound: E. Caesar Chavez Ave to Valley View Ave. exits | 40 | 22 |
| New York | 10.2 | Brooklyn Queens Expressway Southbound: NY-25A/Northern Blvd. to NY-27 | 31 | 18 |
| Los Angeles | 8.1 | I-405 Southbound: Nordhoff St. to Mulholland Drive | 22 | 14 |
| New York | 6.2 | Van Wyck Expressway Southbound: Horace Harding Expy to Linden Blvd | 20 | 13 |
| Pittsburgh | 3.4 | I-376 Eastbound: PA 50 to US-19/PA-51 | 13 | 9 |
| San Francisco | 5.8 | CA-4 Eastbound: Bailey to Somersville roads | 16 | 11 |
