New study from Ryerson's THRILL lab suggests rider actions cause of most amusement ride injuries

Newswise — Plummeting down a steep hill on a giant roller coaster or whirling at high speeds are annual summer rituals for thrill-seeking amusement riders. While amusement ride injuries are a rare occurrence, most occur as a result of rider behaviour. Ryerson University Professor Kathryn Woodcock, School of Occupational and Public Health (OPH), director of the university’s THRILL (Tools for Holistic Ride Inspection Learning and Leadership) lab and a certified professional ergonomist, is investigating how modifying a ride to correspond to rider behaviour can make the experience both safe and enjoyable.

“If new equipment, and even classic carnival rides, could be modified to work with riders’ intuitive behaviour, we could expect the chance of human errors to be reduced,” said Woodcock, author of a new study on amusement ride safety that focuses on the human behaviour that preceded ride accidents officially investigated in California between 1998 and 2005. The study, which was completed with the help of recent Ryerson OPH graduate Zahrah Diyaljee, analyzed data from the investigation reports of 37 amusement ride accidents involving the injury of one or more riders. The findings will provide important information for accident investigators across North America.

The error-tracing method used in this study is being developed into an interactive menu-based tool to assist accident investigators who may have little knowledge of human-factors engineering. Using this tool, investigators will know immediately whether or not they have collected enough information to classify a particular rider error. The tool will also advise how to further probe the factors underlying the error and suggest best solutions.

It was discovered that 58 per cent of investigations lacked precise clarification or in-depth exploration by accident investigators. Moreover, many of these “gaps” may have pointed to factors that are not typically considered in investigations, including design modifications that would lessen the likelihood of human error.

“This is a significant concern,” said Woodcock, “considering the vast majority of amusement ride injuries are linked to patron actions.”

Previous THRILL studies have shown that accidents are commonly the result of riders seeking new sensory experiences or trying to communicate with their companions. Riders often choose unsafe ways to accomplish these goals because they have misleading or inadequate information about their immediate environment, or because they don’t remember safety instructions during the actual ride experience.

Ride design can also help shape behaviour of riders. A “teacup” ride provides a good example. To increase the spinning effect and make the ride more exciting, riders can grasp and turn the wheel, with the benefit of keeping their hands and arms inside the ride. Conversely, when riders do unsafe actions such as hanging over the side or lying down, the spinning promptly slows down. Several theme parks have now introduced interactive rides that enable riders to modify their ride experience to be more thrilling or tamer, if the guest prefers.

Woodcock’s paper, Human-Factors Antecedents in California Amusement Ride Accident Investigations, received research and financial support from Saferparks, a California-based consumer advocacy organization. The THRILL research lab is funded by the Natural Sciences and Engineering Research Council of Canada.

Woodcock will present her findings in September at an annual meeting of the Human Factors and Ergonomics Society in San Francisco.

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