In 2003, Exponent completed an independent engineering evaluation of the safety of roller coasters for Six Flags, Inc—the world’s largest regional theme park company. Exponent and the American Association of Neurological Surgeons conducted the studies. Exponent evaluated data and information on roller coaster incidents, assessed potential risks, and conducted new measurements related to g-forces and roller coasters. We also performed a comprehensive analysis of government injury data on amusement park ride safety.
Exponent looked at data for 167 roller coasters and performed a computer analysis of 34 Six Flags’ roller coasters, and found that while the top speeds on roller coasters have increased over time, maximum accelerations have remained essentially unchanged. Our engineers conducted tests to measure the maximum g-forces of several common activities and compared them to the g-forces on roller coasters. We also performed computer modeling of the effects that g-forces on roller coasters would have on riders to evaluate the assertion that roller coaster g-forces might be able to create G-LOC (a “g-induced loss of consciousness”). Exponent found that the g-force levels on rides evaluated do not cause injuries and that the durations of the accelerations on these roller coasters are so short that they will not cause a loss of consciousness even for the people who may be the most susceptible to G-LOC. In summary, the speeds on these roller coasters may be high, but the g-forces of roller coaster rides take place in a short period of time and can be similar to everyday disturbances that people experience.
Our statisticians conducted an extensive review of 22 online databases of literature to obtain data on accidents associated with amusement park attractions, roller coaster design, occupant kinematics, occupant injury reports, and the medical facts behind reported associated injury types. We also conducted a detailed examination of the data of the Consumer Product Safety Commission (CPSC) and found that by analyzing the CPSC data as well as internal accident data provided by Six Flags, that the number of reported injuries at fixed-site amusement parks are very small. Moreover, the data show that more than 94% of injuries that required emergency room visits did not involve injuries that were serious enough to require hospital admission. We also found that the CPSC data do not show increasing neurological injuries associated with rides.