If you're looking for a way to gauge the health of the U.S. economy this summer, consider regional amusement parks — parks that you can drive to within a few hours. Some 260 million people spend about $10 billion annually at regional theme parks, and this year is shaping up to be a record-breaker.

To understand what's driving those numbers, there are few better people to spend a day at a park with than Martin Lewison.

"As of today, I've been on 1,306 different roller coasters," Lewison says.

He picked up his latest tally mark at Lake Compounce in Bristol, Conn. Built in 1846, it's the nation's oldest amusement park.

Besides being an enthusiast, Lewison makes his living researching the industry at Farmingdale State College in New York. He says successful amusement parks understand their customer.

"When you've been to your local park year after year after year, you don't want to go back if there's nothing new," he says.

Translation: More rides bring in more customers.

But big steel coasters are expensive to plan, design and build — usually $15 million to $25 million. Just a few years ago, the biggest operators of American regional parks, Six Flags and Cedar Fair, couldn't afford that.

"Five years ago, Six Flags was emerging from bankruptcy, Cedar Fair was trying to sell itself to a private equity firm for a fire sale price," Lewison says.

Those days have passed. Cedar Fair reported record revenues for the first half of 2015, up 5 percent from last year. The company highlighted capital improvements for its growth, or in other words, more rides.

There's no place better to see these capital improvements than Cedar Fair's flagship park, Cedar Point, on the shores of Lake Erie in Sandusky, Ohio.

"We are in the roller coaster capital of the world," said the park's general manager, Jason McClure.

Around the park steel tracks rise, bend and twist in innovative ways. The big-ticket coasters can be solid investments for years. Consider Top Thrill Dragster, which debuted a dozen years ago as the world's tallest coaster at 425 feet. It's now the second tallest.

McClure narrates as riders sit, strapped in, waiting for launch. "So they come up to the light post with the green, yellow, red, and the guests are waiting to be launched, zero to 120 mph in 3.6 seconds."

The ride looks like a massive horseshoe. The cars shoot straight out on the track for about 100 yards, then turn straight up, bend over a curve, then plunge straight back down. People will wait two hours for this 19-second thrill.

There are other ways to spend time here besides being scared stiff, and, by extension, ways for the park to earn money. Fifty-five percent of Cedar Fair's revenues come from ticket sales. The rest is from food, merchandise and games. And accommodations — Cedar Point renovated its on-site beachside hotel this year to encourage patrons to stay longer.

Lewison says parks have gotten better at digital marketing. Good weather and low gas prices are also helping drive up attendance. Still, Lewison always comes back to the rides, and on that front, the future looks bright.

"They've proposed a 500-foot-tall skyscraper coaster in Orlando, and everybody's crossing their fingers for that to happen," he says.

Well, maybe not everybody — 500 feet may not be for the faint of heart.

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