New research shows increased automobile crash rates among teen drivers who start school earlier in the morning.
Results, published in the April 15 issue of the Journal of Clinical Sleep Medicine, indicate that in 2008 the weekday crash rate for 16- to 18-year-olds was about 41% higher in Virginia Beach, Va, where high school classes began at 7:20 – 7:25 am, than in adjacent Chesapeake, Va, where classes started at 8:40 – 8:45 am.
There were 65.8 automobile crashes for every 1,000 teen drivers in Virginia Beach, and 46.6 crashes for every 1,000 teen drivers in Chesapeake. Similar results were found for 2007, when the weekday crash rate for Virginia Beach teens (71.2) was 28% higher than for Chesapeake teens (55.6). In a secondary analysis that evaluated only the traditional school months of September 2007 through June 2008, the weekday crash rate for teen drivers was 25% higher in Virginia Beach (80.0) than in Chesapeake (64.0). An investigation of traffic congestion in the neighboring cities did not reveal differences that might account for the teen crash findings.
"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. "The study supported our hypothesis, but it is important to note that this study does not prove cause and effect. 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."