Teen Crash Rates Spike With Earlier School Start Times

A new study indicates there may be an increased risk of automobile crashes among teenage drivers who start school earlier in the morning.Researcher analyzed the crash rates of students who attended high schools in two Virginia school districts, Virginia Beach and Chesapeake.  In Virginia Beach, high school classes began at 7:20-7:25 a.m. –  over an hour earlier than the adjacent Chesapeake district, where classes began at 8:40 – 8:45 a.m.

The weekday crash rate for teen drivers in Virginia beach was 25 percent higher (80 crashes for every 1,000 students) than the rate for teen drivers in Chesapeake (64 crashes for every 1,000 students).

Researchers said traffic congestion was similar for both cities and unlikely to have accounted for differences in crash rates.

“We were concerned that Virginia Beach teens might be sleep restricted due to their early rise times and that this could eventuate in an increased crash rate,” said lead author Robert Vorona, MD, associate professor of internal medicine at Eastern Virginia Medical School in Norfolk, Va, in a press release.  “We are planning to perform subsequent studies to follow up on these results and to investigate other potential ramifications of early high school start times.”

According to the American Academy of Sleep Medicine, the average teen needs a little more than nine hours of sleep each night.  However, chronic sleep restriction is a common problem among teens because biological changes that occur during adolescence shift the onset of sleepiness later in the night.

Researchers believe the delay can make it a challenge for teens to get enough sleep when they have to wake up early for school.

Vorona suggested that starting high school later in the morning may promote driver alertness and potentially decrease crash rates by allowing teens to get more sleep at night.

“We believe that high schools should take a close look at having later start times to align with circadian rhythms in teens and to allow for longer sleep times,” he said.  “Too many teens in this country obtain insufficient sleep. Increasingly, the literature suggests that this may lead to problematic consequences including mood disorders, academic difficulties and behavioral issues.”

Previous studies have shown that delaying school start times by one hour could also enhance students’ cognitive performance by improving attention and increasing rate of performance, as well as reducing mistakes and impulsivity.

The study was published in the Journal of Clinical Sleep Medicine.