(NEW YORK) -- If you live in one of the largest U.S. metropolitan areas, you may want to allot yourself some extra time before hitting the road to make that doctor's appointment or job interview.
A report out Tuesday by the Texas A&M Transportation Institute finds that taking what should be a 20-minute trip can take as long as two hours in the nation's most congested cities because of traffic.
Washington, D.C., is the worst offender this year, followed by Los Angeles, San Francisco-Oakland, New York-Newark and Boston. Houston, Atlanta, Chicago, Philadelphia and Seattle rounded out the Urban Mobility Report's top 10 list of the most congested cities in the U.S.
According to the annual report, congestion cost drivers an extra 5.5 billion hours in their cars and an additional $121 billion in gas in 2011 alone.
While congestion is down from its peak in 2005, conditions on the road are expected to get worse as the economy continues to improve.
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