The 40 million Americans traveling by trains, planes or automobiles this Fourth of July weekend will have fewer fellow travelers to contend with, as the tight economy forces many people to stay at or close to home.

For the first time in a decade, the number of Americans traveling for this holiday is expected to decline, by 1.3 percent, according to Triple-A.

"Clearly, we've already reached a breaking point of some sort," Triple-A's Marie Montgomery told CBS News Transportation Correspondent Nancy Cordes, with the average price of gas topping $4 a gallon nationwide, air fares up 13 percent since last Independence Day, and car rental prices up 12 percent in that time.

The biggest drop-off is among those who'd ordinarily drive, down 12 percent since last July 4th, Triple-A says. The majority of people traveling by car will be in the southeast, and the majority of air travelers will be in the west, Cordes says.

Gas prices are "definitely having an impact on your everyday life," Montgomery observes, forcing some many families to scrap holiday plans.

The Jacobs family, in Baltimore, passed on a planned beach vacation because it was just too expensive.
 
"To down and see everybody would have been a great opportunity, but it just -- financially -- just wasn't doable," Julie Jacobs says.
 
As for those still planning to head out of town, "A lot of the people who maybe would normally take plane trips this summer are driving instead because, believe it or not, even at these very high gas prices, it's still cheaper to drive than to fly to a lot of destinations," Montgomery points out.

And, says Cordes, "This is the last holiday before Labor Day, when some airlines plan to start significantly reducing service to certain cities. Between those cutbacks and additional charges for everything from baggage to your once-complimentary drink, consumers will surely find future flights even tougher on the wallet."