Adolescent sleep, school start times, and teen motor vehicle crashes

J Clin Sleep Med. 2008 Dec 15;4(6):533-5.


Study objectives: To assess the effects of delayed high-school start times on sleep and motor vehicle crashes.

Methods: The sleep habits and motor vehicle crash rates of adolescents from a single, large, county-wide, school district were assessed by questionnaire before and after a 1-hour delay in school start times.

Results: Average hours of nightly sleep increased and catch-up sleep on weekends decreased. Average crash rates for teen drivers in the study county in the 2 years after the change in school start time dropped 16.5%, compared with the 2 years prior to the change, whereas teen crash rates for the rest of the state increased 7.8% over the same time period.

Conclusions: Later school start times may both increase the sleep of adolescents and decrease their risk of motor vehicle crashes.

MeSH terms

  • Accidents, Traffic / statistics & numerical data*
  • Adolescent
  • Automobile Driving / statistics & numerical data*
  • Data Collection
  • Female
  • Humans
  • Kentucky
  • Male
  • Schools / organization & administration*
  • Sleep / physiology*
  • Time Factors