Here are some facts about roller coasters:

• More than 2,000 roller coasters are operating worldwide.

• Coasters are made of wood or steel, with speeds ranging between about 40 and 128 mph.

• The world's tallest coaster is Kingda Ka, measuring 456 feet at the Six Flags Great Adventure park in Jackson, N.J. Kingda Ka also boasts the world's tallest drop at 418 feet.

• The largest number of roller coasters in one park can be found at Cedar Point in Sandusky, Ohio, where 17 are operating.

• The oldest operating roller coaster is Leap-The-Dips at Lakemont Park, Altoona, installed in 1902.

From the American Coaster Enthusiasts Web site and Wikipedia's list of roller coaster records.