Honolulu, a vacation draw for its beaches and weather, was the most congested U.S. city in 2011, dethroning Los Angeles, an Inrix Inc. study found.

Drivers in the city, the state of Hawaii’s largest, wasted an average of 58 hours stuck in traffic last year, compared with 56 hours in Los Angeles, according the Inrix National Traffic Scorecard, released today. Honolulu jumped to No. 1, from No. 37 a year earlier, because of a change in the way Inrix counted congestion, said Jim Bak, co-author.

“We’ve shifted to focus on travel time for individual drivers, rather than overall congestion,” Bak said in a telephone interview. “L.A. has 15 times more people and 20 times the roadways of Honolulu, so at the system level, it obviously has much greater overall congestion.”

Congestion across the U.S. eased about 30 percent in 2011, the result of sluggish economic growth, according to the study. The decline was the steepest since 2008, when congestion fell 34 percent, according to Kirkland, Washington-based Inrix, a provider of traffic data-services to clients such as Ford Motor Co., MapQuest Inc. and Microsoft Corp.

Following Honolulu and Los Angeles in urban congestion were San Francisco; New York; Bridgeport, Connecticut; Washington; Seattle; Austin, Texas; Boston; and Chicago. Los Angeles and New York each had four of the 10 most-congested traffic corridors in the U.S., according to the study.