The reason, as a surly economist might say? It's the economy, stupid.
"The economy is in such bad shape. ... They're still really hesitant to take that trip," said Beth Mosher, spokeswoman for AAA Chicago.
In comparison, over the July 4 weekend when gas prices were far higher than the same weekend the previous year, the number of travelers dropped just 2.3 percent, she said. At that time, the economic news wasn't as dire as it is now.
For airlines, the lowered fares at a time when they usually can mark them up can't combat the extra fees the struggling industry has tacked on to everything from checked baggage to pillows to in-flight food.
"For a family of four, it's a $100-$150 difference," Mosher said of the baggage fee, which some airlines charge even for the first bag, with an additional charge for the second.
Mosher said that even with the dropping fare prices, the 4.54 million people expected to fly during the long holiday weekend is 7.2 percent less than the 4.89 million who did the same last year.
Graeme Wallace, chief technical officer for farecompare.com, a consumer airline ticket research Web site, said it may take until after the first of the year before airlines know if the recent fare reductions will put many more people on planes. He said in his recent experience, business flights have been crowded but leisure flights are often half empty.
"With the economy tanking, they're thinking, 'Do I want to spend $400 for a 1,200 mile trip?"' Wallace said.