The trend began after 9/11, she and other analysts say, as more American families decided to forgo travel abroad and sought ways to entertain themselves within the US.
Now, at park chains from Disney to Universal, from Six Flags to Cedar Fair, the idea has continued to blossom. Parks are cleaner and more visitor-friendly: They have designated smoking areas, "misters" to stay cool while waiting in line, and more places to sit and relax.
"Many parks have gone out of their way to improve the entire experience of the theme park visit," says Paul Ruben, North American editor for Park World, a theme-park trade publication. More are offering discounts, package deals with nearby – often competing – parks, and ways to reserve seats for high-priority rides without having to wait in line.
"For years they thought the way to increase attendance was to bring in a compelling new thrill ride, but now they are realizing that things got out of balance and the family got left behind," says Mr. Ruben.
The trend may be more self-preservation than altruistic, Ruben and others say. Six Flags, the world's largest regional theme park company with 28 US parks has run into financial difficulties in recent years as attendance dropped. Observers cite the chain's reputation for being teen-dominated.
New CEO Mark Shapiro, who took over last December, is trying to recast that image. He recently said the company will consider selling six properties including Six Flags Magic Mountain, in part because of its "rowdy teenage atmosphere," the Associated Press reported.
"We are trying to reset the balance between teens and families," says Six Flags's spokeswoman Wendy Goldberg. "There were a few years of letting the brand go down a bit. There was the perception that Six Flags was good only for teens, not kids and adults."