In a perfect world, an ample supply of a commodity at a low price should stimulate demand. Not so with gasoline in America. According to MarketWatch, "Even though prices at the pump are now about 45% lower than they were a year ago and significantly below $2 a gallon, 52% of Americans told Gallup that they have not gone back to their old gas-guzzling ways."

The poll indicates, as might be expected, that lower income drivers are cutting back the most.

The easy reasoning behind the drop in driving is that people will save money in a tough economy. If things were good, drivers would drive more and take advantage of falling prices.

It may not be that simple. The average American is not a boob. He understands that, over time, the amount of oil in the world is finite. Gas prices may not go back up tomorrow, but they will go back up. Getting used to using oil-based products less is good long-term thinking.

Another, less obvious, reason for cutting back on hours on the road is that a car driven less lasts longer. Buying gas may be getting less expensive, but a new car is still an investment of over $20,000 in most cases. People don't have that money. Getting another year of service out of an aging vehicle has a particularly important value in a recession.

Douglas A. McIntyre is an editor at 247wallst.com.