Changes are being made in the entry and exit areas of Primeval Whirl -- including the installation of sensor mats in a restricted-access area where a Disney worker was reportedly struck by a roller-coaster car Nov. 24. Karen Price, 63, fell and hit her head, and died of her injuries a few days later. The U.S. Occupational Safety and Health Administration is still investigating the death.

The accident, said Disney World spokeswoman Kim Prunty, led the company "to consider additional safety enhancements."

"We are always looking at ways to enhance safety," she said.

On the off-limits area of the ride platform beyond the passenger loading and unloading zones, Disney is installing sensor mats that will shut down the ride if someone sets foot there, Prunty said. Also, bold striping is being added to delineate the loading and unloading zones.

The work, which is being done after hours, should take a few weeks and should not disrupt ride operations, Prunty said.

Primeval Whirl is an old ride design known in the trade as a "wild mouse," featuring cars that travel independently through a series of close, tight curves. There are dozens of such rides all over the world, some dating back more than 50 years. It is considered a relatively mild roller-coaster design, with a good safety record for riders.

Since Primeval Whirl opened in April 2002, there has never been a reported case of a rider hurt seriously enough to require inpatient hospital treatment, though Disney currently faces a lawsuit from a man who alleges he seriously injured his knee while getting off the ride in 2005.

Primeval Whirl, in Animal Kingdom's Dinoland U.S.A. carnival area, is actually two coasters woven together. According to the independent Web site rollercoasterdatabase.com, each of the two tracks is 1,377 feet long and rises 42 feet in the air, and the cars reach a maximum speed of 29 mph.