A ten-year-old kid on an adult-sized, all-terrain vehicle (ATV) barrels through the woods behind his house. He swerves to the right to avoid a tree stump. He blinks. Before he knows it he veers off the path and up a dirt hill. The five-hundred-pound ATV tilts to one side, flips over, and crushes him.

ATV crashes involving riders under the age of sixteen continue to be a source of serious injuries and fatalities, even when riders are required to wear helmets, according to a study published in the journal Pediatrics. Study coauthors were Heather Keenan, who conducted the work while an assistant professor of social medicine at UNC-Chapel Hill, and Susan Bratton of the University of Michigan. They collected injury and fatality data from trauma centers, hospitals, and death reports in Pennsylvania, which has ATV regulations, and in North Carolina, which does not. The researchers then compared the data to determine if regulations were having the effect intended.

Several states allow ATV riders to be as young as twelve, and twenty-three states do not have minimum age laws at all, according to the Specialty Vehicle Institute of America, an industry trade group. Some states such as Pennsylvania require helmet use and restrict driving or riding. Pennsylvania does not allow children under ten years old to ride ATVs on public lands or recreation areas and requires special permits for children under sixteen years old to ride. Other states such as North Carolina have no such restrictions.

Currently, riders under the age of sixteen make up 33 percent of ATV deaths, according to the Consumer Products Safety Commission (CPSC). The American Academy of Pediatrics recommends that children under sixteen be prohibited from riding or driving ATVs. “Young children don’t have good judgment, and ATVs are fast and heavy,” Keenan says. “So it can be very easy to be injured in a crash.” Keenan and Bratton identified 1,080 injuries in children under the age of sixteen between 1997 and 2001 in Pennsylvania and North Carolina. A total of seventy deaths in the same age group occurred in the two states — forty-three in Pennsylvania and twenty-seven in North Carolina.

When they compared the data, what Keenan and Bratton found was consistent with the intent of the Pennsylvania ATV regulations. The proportion of children under eleven years old injured in North Carolina (35.1 percent) was higher than in Pennsylvania (27.8 percent). The proportion of helmet use was lower in North Carolina (16.7 percent) than in Pennsylvania (35.8 percent). And in Pennsylvania the proportion of crashes by children in state parks was lower. These data support the American Academy of Pediatrics’ recommendations for enacting ATV regulations, the study says.

But despite regulations, many children still suffer serious injuries or death. “What we found was that helmets were protective against head injuries, but because of the high speeds and weight of the ATV, many children suffered spinal, chest, and abdominal injuries,” Keenan says.

Between 1997 and 2001 the number of ATV injuries in children and adults almost doubled, outpacing the 40 percent increase in the number of ATVs, according to reports by the CPSC. The number of ATV injuries hasn’t been that high since the mid-80s, when three-wheeled ATVs were prevalent across the United States. Since 1988 the sale of new three-wheeled ATVs has been banned, but there are currently no national regulations regarding the use of four-wheeled ATVs; nor are there any restrictions on the driver’s age, the study says.