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."
Comments
Various Ways to Measure Congestion Costs
Traffic congestion can be measured in various ways which lead to different conclusions about the magnitude of this problem and its solutions. The INRIX Scorecard and the Texas Transportation Institute's Travel Time Index measure the intensity of congestion for motorists, but do not account for the portion of total urban travel by automobile or average trip distances, and so fail to recognize the congestion costs that are avoided in cities with better transport options and shorter travel distances. A much better indicator is per-capita annual congestion delay, which tends to be lower in smart growth cities. For information see my recent blog, "Threats of Gridlock are Greatly Exaggerated" (http://www.planetizen.com/node/48451 ) and Joe Cortright's report "Driven Apart: How Sprawl is Lengthening Our Commutes and Why Misleading Mobility Measures are Making Things Worse" (www.ceosforcities.org/work/driven-apart ).
Todd Alexander Litman
Victoria Transport Policy Institute
www.vtpi.org
"Efficiency - Equity - Clarity"