ORLANDO, Fla. — Attendance at North America's 50 most popular amusement parks rose 4.2 percent in 2005, powered by strong investment in new rides, the 50th anniversary of Disneyland and a hurricane season that bypassed the theme park capital of Orlando.

An estimated 176 million visitors went to North America's most popular parks, according to an annual survey released Monday by the trade publication Amusement Business and the research firm Economics Research Associates.

Attendance was off at two Ohio facilities in the publication's list of the top 25 best-attended North American amusement parks. Paramount's Kings Island in southwest Ohio had 3.3 million visitors in 2005 to place 16th, but was down 5.1 percent overall.

Cedar Point in Sandusky, Ohio, had 3.1 million, good enough for 18th but off 2 percent from last year.

Worldwide, amusement park attendance increased 2.2 percent to 253 million visitors in 2005.

Most major parks don't release their attendance figures, but the Amusement Business numbers are considered the most reliable estimates in the industry.

The Cedar Fair parks saw attendance rise 1.6 percent. But its California-based Knott's Berry Farm park declined 3 percent, mainly because of a rainy first quarter, and its flagship Cedar Point park in Ohio declined despite the introduction of the maXair ride.

Cedar Point planned to lower admission prices by $5 a ticket, a counterintuitive move in an industry that annually raises its prices. The goal is to have more people go through the turnstiles in a market that has struggled economically with layoffs in the automotive industry, said Brian Witherow, a Cedar Fair vice president. The Sandusky-based park's three biggest markets are Detroit, Cleveland and Toledo, Ohio.

"Clearly, we can't control things like gas prices and unemployment rates in our core market . . . but one thing we can control is the admission price," Witherow said.

Neither a rainy spring in California nor a parade of destructive hurricanes in the southeast slowed down growth in the $10 billion industry, which had strong momentum from last year, the first year attendance had increased since the 2001 attacks hobbled the U.S. tourism and travel industry.

Those parks that acquired new rides in 2005 saw their investments pay off while those parks that had an off-year in their capital investment cycle, for the most part, experienced attendance dips, said James Zoltak, editor of Amusement Business.

Universal's two parks in Orlando, Universal Studios and Islands of Adventures, each saw declines of 8.5 percent, while attendance at Universal Studios Hollywood dipped 6 percent. All three parks came off strong attendance increases in 2004 and the parks in 2005 didn't introduce an excitement-generating thrill ride comparable to 2004's Revenge of the Mummy ride.

Tom Schroder, a Universal spokesman, said 2004's highflying attendance figures were a tough act to follow.

"The bar was raised so incredibly high for us by spectacular attendance in 2004, combined with a very competitive environment to higher gas prices," Schroder said. "2005 was just slightly less great than 2004."

Amusement Business also said a worldwide marketing juggernaut highlighting the 50th anniversary of Disneyland at Disney's parks around the world may also have siphoned off some attendance at the Universal parks.

The Walt Disney Co.'s four parks in Florida and two parks in California benefited from the celebration with new rides, stage shows and parades. The Florida parks had attendance increases of between 5 percent and 6.5 percent, while Disneyland and Disney's California Adventure in Anaheim, Calif. respectively saw growth of 8.5 percent and 3.6 percent.

The Magic Kingdom at Walt Disney World in Orlando, with 16.1 million visitors, and Disneyland in California, with 14.5 million visitors, were not only the two most visited parks in North America in 2005, but they were the best-attended parks in the world. In North America, the remaining top 5 spots were filled out with Disney's other Florida parks: Epcot, Disney-MGM Studios and Animal Kingdom.

Disney parks in the United States, Japan and France took up the top eight spots in attendance worldwide.

"We think that certainly the 50th anniversary of Disneyland has resonated with consumers, not just here in California but really all over the world," said Lisa Haines, vice president of strategic communications at Walt Disney Parks & Resorts.

Six Flags Inc., which invested $135 million in new rides around the nation for the 2005 season, was rewarded with a 5.7 percent increase across the chain, according to Amusement Business. The opening of a water park at its Six Flags Great America park in Gurnee, Ill. helped boost attendance by 24 percent.

Anheuser Busch-owned parks saw sharp increases at locations with new thrill rides. Busch Gardens Tampa Bay added the Sheikra ride this year and saw an attendance boost of 5.1 percent, while Busch Gardens in Williamsburg, Va. added the DarKastle thrill ride and had 8.3 percent jump.

Viacom Inc.'s Paramount Parks unit had a chainwide increase of 2.2 percent.