People finally driving less -- good!

With gas prices rising steadily over the past decade -- even before the recent levitation -- there's been a question nagging at economists: at one point would consumers break? When would the elasticity of demand start to show? Obviously Americans would drive a lot less if gas were $35 per gallon, but at would point would consumption start to slow.

2008 appears to be the year, and $4 appears to be the beginning of the breaking point. Cambridge Energy Research Associates reports that "U.S. gasoline demand will likely decline in 2008 for the first time in more than 17 years. For the first time since the 1970s and early 1980s the number of miles driven by Americans has clearly begun trending downward."

In April, Americans drove 1.8% fewer on public roads compared to the same period last year, the sixth consecutive month of declines.