In the 1970s, disco-theme skating rinks were all the rage. In the ’80s, it was paintball battlefields, followed in the ’90s by urban skateboard parks.

And now comes the zip line – an elevated cable ride that zips harnessed riders downhill at high speeds, powered only by gravity.

Across the nation, these rides stretch over canyons, vineyards, island tourist towns and even zoos. Since 2001, the number of zip lines built in the United States has soared from 10 to more than 200, according to zip line experts.

In the Carolinas, ziplines are popular -- and plentiful.

At the U.S. National Whitewater Center in Charlotte, there’s the Mega Zip, where riders fly over the rapids along a 1,123-foot zip line, and the Canopy Tour, where riders travel along a series of zips and other high-flying challenges. The longest zip in the tour is 560 feet.

The Canaan Zip line Canopy Tour in Rock Hill features six lines, all over the Catawba River. And the outdoor Xtreeme Challenge in Monroe includes two zip lines that go over a lake on the property.

Nationally, zip lines “are spreading like fast-food hamburger joints,” said Mike Teske, technical director for a Maui-based zip line company who also heads a panel drafting national safety standards for zip lines.

The craze is fueled by a resurgence in the popularity of outdoor activities, greater availability of insurance, and cheaper construction costs for zip line platforms due to the housing slump, according to builders and operators. The prices to ride vary widely: It costs $10 to ride an 800-foot zip line at a KOA camp in Santa Paula, Calif., for instance, but $112 to ride two zip lines at the San Diego Zoo Safari Park.

In addition, builders and operators point out, zip lines have wide appeal to both young and old. The only physical demand is the climb up the steps of the platforms, where guests wearing harnesses are hooked to a pulley that allows them to travel along the zip lines’ steel cables, with typical speeds reaching 35 to 45 mph and faster. The most advanced zip lines have built-in brakes. On the basic models, riders must slow themselves with a gloved hand.

Like roller skating and paintball battles, the promise of an adrenaline rush draws many first-time riders.

“I tried it because going to the movies and going bowling is getting boring,” Tyler Montague, 21, a graphic design intern from Huntington Beach, Calif., said after a three-hour tour at Action Zipline Tours in the mountains near Big Bear Lake in California.

Other riders say they try a zip line once – just to check it off their before-you-die bucket list.

“I’m 64 years old, and I don’t think I’ll do it again,” John Rockwood, a retiree from Buffalo, N.Y., said after joining his wife, Julia, on the Big Bear zip line.

Zip lines have become such a boom industry, particularly in California, that a private group is setting new voluntary safety standards for these rides.

The guidelines are being written by Pennsylvania-based ASTM Inc., formerly known as the American Society for Testing and Materials. The group has previously drafted safety rules for helmets, medical devices and steel products. The work began two years ago, and officials estimate that the voluntary rules could be drafted in the next year or two.

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