title: High school off-campus lunch policies and adolescent motor vehicle crash risks.
abstract: OBJECTIVE
  To examine differences in motor vehicle crash involvement for teenagers in communities with and without school policies enabling teens to drive off campus during lunchtime.
  
  
  METHODS
  Comparison of lunchtime motor vehicle crashes involving teen drivers in two North Carolina counties having open-lunch policies with a third county without an open-lunch policy. We also compare crash rates during the before-school period and at all times of the day in the three counties. Data were analyzed by computing rate ratios of teens' involvement in a crash during the three time periods and comparing them among the three counties.
  
  
  RESULTS
  Crash rates over the lunch hours were significantly higher for teenagers in the counties with open-lunch policies, despite these counties having no elevated crash risk during other time periods. This resulted in a relative risk of lunchtime crash involvement of 3.10 and 2.98 (95% CI 1.97-4.89 and 1.87-4.74, respectively) compared with the county without an open-lunch policy. Number of vehicle occupants also increased during the lunch hours in the counties with open-lunch policies.
  
  
  CONCLUSIONS
  Open-lunch policies contribute to motor vehicle crashes in teenagers and encourage a situation where there are multiple occupants per vehicle, a known risk factor for teenage motor vehicle crashes.
authors.affiliation: University of North Carolina School of Medicine, Chapel Hill, North Carolina, USA. lstone@unch.unc.edu
authors.forename: Lorraine M
authors.initials: LM
authors.lastname: Stone
authors.forename: Carol W
authors.initials: CW
authors.lastname: Runyan
mesh_terms: D000063:Accidents, Traffic / Q000706:statistics & numerical data*; D000293:Adolescent; D000294:Adolescent Behavior; D005247:Feeding Behavior; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D009657:North Carolina / Q000453:epidemiology; D011640:Public Policy; D012307:Risk Factors; D012574:Schools; D013997:Time Factors