COLLEGE STATION - The Texas Transportation Institute released its 2007 Urban Mobility Report this week, finding that traffic congestion continues to worsen in American cities of all sizes.

According to the report, the congestion accounts for a $78 billion annual drain on the U.S. economy in the form of 4.2 billion lost hours and 2.9 billion gallons of wasted fuel.

Researchers describe the report as the “most detailed picture yet” of a problem they say is growing worse in all 437 of the nation’s urban areas.

“There is no ‘magic’ technology or solution on the horizon because there is no single cause of congestion,” said co-author Tim Lomax, a research engineer at TTI. “The good news is that there are multiple strategies involving traffic operations and public transit available right now that if applied together, can lessen this problem.”

The 2007 mobility report indicates the average peak period traveler spends an extra 38 hours of travel time and consumes an additional 26 gallons of fuel as a result of the congestion, amounting to a cost of $710 per traveler. Along with expanding the estimates of the effect of congestion to all 437 U.S. urban areas, the study provides detailed information for 85 specific urban areas.

The report also focuses on problems presented by what it describes as “irregular events” such as crashes, stalled vehicles, work zones, weather problems and special events that can cause unreliable travel times and contribute to the overall congestion problem.

Worsening congestion, the study notes, is reflected in several ways, including trips taking longer with travel times increasingly unreliable. Congestion, it says, also is affecting more of the day, weekend travel, rural areas and freight shipments.

Researchers said they spent two years revising the methodology using additional sources of traffic information to provide more and higher quality data on which to base the current study.

The report identifies multiple solutions to the congestion problem that, researchers say, must be used together to be effective, the researchers said. These include:

Get as much service as possible from existing infrastructure Add road and transit system capacity in critical corridors Relieve chokepoints Change usage patterns Provide choices Diversify the development patterns Keep expectations realistic

“Congestion is a far more complex problem than is apparent at first glance,” Lomax said. “The better the data we use to define the problem, the more successful we will be in addressing its root causes.”