NEW YORK (CNN/Money) - Go West, young man, but be prepared to sit in traffic when you get there.

A new study shows traffic congestion is getting worse all across America. But the dubious honor of the city with the most crowded roads goes to Los Angeles, according to the Texas Transportation Institute at Texas A&M University. San Francisco is a close second.

The study looked at traffic patterns in 75 cities, taking into consideration such factors as length of travel delays per capita, and how much extra travel time each trip takes, compared to national averages.

According to the report, Americans waste 5.7 billion gallons of fuel, and lose 3.5 billion hours of potential productivity by sitting in traffic.

"Congestion is worsening, no doubt about that," said Tim Lomax, one of the study's co-authors.

America's Worst Traffic The 10 cities with the most congested driving conditions. Rank  City  1  Los Angeles, CA  2  San Francisco, CA  3  Denver, CO  4  Miami, FL  5  Phoenix, AZ  6  Chicago, IL  7  San Jose, CA  8  Washington, DC  9  Portland, OR  10  Boston, MA   Source:  Texas Transportation Institute

Lomax noted that growth in jobs and growth in congestion go hand in hand. "Areas that are rapidly growing are usually places where traffic is growing, too," he said. "If you add 10,000 jobs, you never add enough transportation capacity to meet the demand."

The study also noted that rush hours have grown worse, relative to off-peak driving hours, over the past 20 years. In 1982, the average trip taken during rush hour took 13 percent longer than the same trip would take driving off peak. Today, congestion means a rush hour trip takes 39 percent longer than an off-peak drive.

Some surprises -- such as New York's ranking far outside of the top 10 -- reflect the fact that the report measures "mobility" not just traffic.

Cities with large, relatively efficient public transit sytems are rated positively, because a commuter on a train is generally in motion toward a destination during the trip. In places like Los Angeles, most people get in their cars and park them on the freeway each morning.

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"Each city needs its own 'bag of tricks' to address this growing problem," said Lomax.

Given a mix of possible options to reduce congestion -- high-occupany vehicle lanes, time-variable toll pricing, road construction, mass transit -- the study emphasizes flexibility as an effective public policy response.

"Areas that are most successful in dealing with transportation issues take a multi-modal approach," according to Lomax.

The report's findings are sure to strike a chord with anyone who endures a hellish commute each day.

Even so, there's an element of self-interest implied by the report's sponsors: the American Road and Transportation Builders Association, as well as the American Public Transportation Association. Both groups support public works projects to alleviate crowded transportation conditions.