Final answer:
The majority of persons killed or injured in U.S. traffic crashes in 2009 were occupants of vehicles, with driver error being a significant cause. Head and traumatic brain injuries are among the leading causes of fatality in these crashes.
Step-by-step explanation:
According to the National Highway Traffic Safety Administration (NHTSA), the majority of persons killed or injured in U.S. traffic crashes in 2009 were occupants of vehicles. A range of factors contribute to traffic crashes, with driver error being a significant one. As reflected in studies, driver error is associated with approximately 54% of all fatal auto accidents. Furthermore, certain age groups tend to have higher incidences of being impacted by traffic crashes, and head and traumatic brain injuries are major causes of immediate death and disability from these accidents, with young children, adolescents, and the elderly being particularly at risk.