On average, says INRIX, traffic is up 10% since 2009. Why?
Population growth and an increase in interstate traffic due to the economic recovery, says INRIX.
They conclude, "When employment returns to 2007 levels, 9 MILLION more daily commute trips than 2010 levels will need to be accomodated, further stressing America's urban highway network."
And predictably, corridors that have the worst congestion will attract more congestion:
"We fully expect-should growth continue and particularly if job growth picks up-to see congested corridors get longer in length, have delays more hours of each day, and see slower traffic while congested. This triple whammy of longer (length), longer (time), and slower is likely to be the primary contributor to congestion growth in 2011, as it appears to have been in 2010."