USA Today's Spin On Mobility Study
"...In the 85 biggest U.S. cities, snarled traffic cost travelers 3.5 billion hours in 2002, up from 700 million in 1982, according to the annual Urban Mobility Report from the Texas Transportation Institute."
See 2004 Mobility Study: Most Congested Cities for the full study.]
The wait for urban commuters in the largest urban areas studies (in hours):
Thanks to Laura Kranz