The higher gas prices that have been plaguing U.S. consumers since the beginning of the year have started to affect their shopping habits. In March, U.S. same-store sales registered a decrease of 0.1 percent, the lowest figure in five years, according to TNS Retail Forward, a Columbus, Ohio-based retail consulting firm. The reason? Faced with higher commodities prices, consumers have been spending less time at the mall, says Ayuna Kidder, a TNS Retail Forward economist.

As of Apr. 14, gas prices in the U.S. averaged $3.79 per gallon, up 22.6 percent from $3.09 per gallon in April 2007, according to the Bureau of Labor Statistics. “Higher gas prices are also related to higher food prices, so consumers are trying to cut down on trips to the mall,” says Kidder.

The sales figures bear this out. According to the March statistics, same-store sales at department stores fell the most, by 10.6 percent, followed by stores in the apparel and accessories sector, which registered a decrease of 7.4 percent. At the same time, same-store sales at standard shopping center fare, like drugstores and warehouse clubs, rose by 3.8 percent and 5.2 percent, respectively.

But while consumers are making fewer trips to the mall — traffic was down 1.1 percent in the first quarter of 2008, reports ShopperTrak, a Chicago-based provider of shopper traffic counting information — they are spending more time on each visit, according to Bill Martin, the firm's president. “They are becoming more organized — instead of going on Saturday and shopping one part of the mall and doing another trip the next day, they do their shopping in a single visit,” says Martin.