Peak oil, according to the great and all-knowing Wikipedia, "is the point in time when the maximum rate of global petroleum extraction is reached, after which the rate of production enters terminal decline." Regardless of your opinions on whether or not the planet has entered into its Peak Oil stage, it would seem that the United States has at least entered the stage of steady decline in usage.
Here's the hard data according to the Associated Press: Americans averaged about 8.2 million barrels of oil, or 344 gallons, per day in 2010, which is an eight percent drop since the country's peak in 2006. Experts seem to agree that gasoline usage in the States will continue to drop – as much as 20 percent by the year 2030, despite millions of additional cars on the roads – barring any unexpected periods of economic boom or another meteoric drop in fuel prices.
Before environmentalists get too excited, though, the falling trend of gasoline usage only applies to the United States, which is still by far the world's largest consumer of oil. Demand from emerging countries, especially China and India, will more than make up for the declining usage in the U.S., leading to an expected record of 88.3 million barrels of oil produced in 2011. The more things change, they more they stay the same...
[Source: The Associated Press via Google | Image: Farther Along via CC 2.0]