PHILADELPHIA (CBS)—One in three high school students have reported traveling with a driver who had been drinking, a new study reveals.

The study, recently published in the Canadian Medical Association Journal Open, examines responses from nearly 25,000 students who answered the Canadian Student Tobacco, Alcohol and Drugs Survey.

Researchers have found that 35 percent of students in Grades 9 to 12 reported riding in cars with drivers who consumed at least one drink within the previous hour.

The study also revealed that about 20 percent of high school students rode in cars with a driver who used marijuana in the previous two hours.

“These numbers are concerning because Canadian youth are at higher risk of death from traffic injuries than any other age group,” said Leia Minaker, lead author on the paper and an assistant professor at Waterloo. “A significant proportion of car-crash deaths are related to alcohol and drug impairment.”

About 9 percent of students in Grades 11 and 12 have driven within an hour of drinking, researchers say.

“The link between alcohol-impaired driving and collision rates is well recognized, but the consequences of marijuana use are less clear,” said Minaker. “As legislation is drafted to regulate recreational marijuana over the coming months, the federal government and the provinces need to prioritize keeping marijuana away from kids, and creating strong policies to reduce marijuana-impaired driving.”

The study also found that while boys were more likely to drive after drinking or using marijuana, girls had higher odds of riding with drivers who had been drinking.

To read more about the study CLICK HERE.