The Wall Street Journal (April 28, 2009) had an excellent article on the dynamics of automobile-based travel in the current economic environment. Americans drive 8.6 billion fewer miles in 2008, part of a longer term decline that began in 2007, according to private sector traffic information provider INRIX. That meant congestion eased in most major U.S. metropolitan areas last year.
Rush-hour congestion -- defined as moving slower than free-flowing traffic -- in the 100 largest U.S. metropolitan markets fell 29% in 2008 versus 2007, said Rick Schuman, a vice president at Inrix, a Washington company that measures traffic patterns. It fell an additional 7% in this year's first quarter.
The fall was the result of two economic events: a dramatic rise in gas prices in the summer of 2008 followed by a slow but deep economic recession that offset falling prices.
In regions most affected -- many of which also have been hit hardest by the housing crunch -- the average travel time fell as much as 10%. Also critical is the reduction of unpredictable traffic jams caused by fender-benders and vehicle breakdowns that frequently accompany congested commutes.
In some cities the drop is more pronounced. Congestion has abated 36% in Atlanta; 57% in Tucson, Ariz.; 68% in Colorado Springs, Colo.; and 70% in Daytona Beach, Fla. In Riverside, where Ms. Caldera lives, it fell by 57%. Among the largest 100 metropolitan areas, congestion shrank in all but Baton Rouge, La.
The decline in miles driven began when gasoline prices crept above $3 a gallon in November 2007. By the time prices began to retreat from their $4-a-gallon high in mid-2008, the number of unemployed Americans began to rise.
No drop of such significance has been previously recorded. With the exceptions of a few short-lived dips during previous recessions, Americans have driven more every year since national record-keeping began.