Starting schools late may help reduce rates of vehicle accidents involving teens: Study

Later school start times are associated with a significant drop in vehicle accidents involving teen drivers, according to a study which may lead to more optimal school time tables which take student safety into account.

The study, published in the Journal of Clinical Sleep Medicine, analysed motor vehicle accident statistics involving adolescents in Fairfax County, Virginia in the US for two school years before and after the implementation of later school start times.

According to the researchers, including those from Boston Children's Hospital in the US, the crash rate in 16-to-18-year-old licensed drivers decreased significantly from 31.63 to 29.59 accidents per 1,000 drivers after the delayed start time.

In contrast, they said the teen crash rate remained steady throughout the rest of the state.

"Accidental injuries including motor vehicle crashes are the number one cause of deaths of adolescents in the U.S., and anything we can do to mitigate that risk should be considered," said study co-author Judith Owens from the Boston Children's Hospital.

"We know from independent data sources that after a change in school start times students get more sleep, which leads to multiple benefits, not just for individuals but also in terms of huge economic implications," Owens said.

The study compared motor vehicle crash rates among adolescents in the differing school start times in Fairfax County, which in the fall of 2015 changed the school start times by 50 minutes from 7:20 AM to 8:10 AM.

It also compared this with data on teenage crashes in the rest of the state, where school start times did not change.

According to the researchers, the later school start time was associated with a lower rate of distraction-related accidents.

"Teenagers who get more sleep are less likely to make poor decisions such as not wearing a seat belt or engaging in distracted driving," Owens said.

"One of the potential mechanisms for this reduction in car crashes is a decrease in behaviours that are related to risk-taking," she added.

The researchers believe that a delayed school start time offers several benefits, including a greater likelihood that teens will get enough sleep on school nights.

Students will be more alert to achieve peak classroom performance, exhibiting reduced tardiness and absences that will improve opportunities for learning, they said.

Owens believes that her study will help other school districts to examine school start times and their relationship to other safety issues beyond car crashes, such as sports-related injuries in student athletes.

"When schools start too early, students are being asked to wake up and function at a time when their circadian rhythm is telling them to stay asleep," she said.

"Changing school start times not only allows students to get more sleep but allows them to sleep at the optimal time. When they sleep may be equally important, if not more so, than how much sleep they get," Owens added.