| Title | School Start Times and Teenage Driver Motor Vehicle Crashes |
|---|---|
| Record ID | 60979 |
| Personal Name Creator |
Foss, Robert D.; Smith, Richard L.; Shi, Funan; O'Brien, Natalie P. |
| Corporate Creator | University of North Carolina at Chapel Hill. Highway Safety Research Center; University of North Carolina at Chapel Hill. Department of Statistics and Operations Research |
| Publisher | University of North Carolina, Chapel Hill |
| Publication Date | 20151200 |
| Language | English |
| Abstract | There is substantial evidence that lack of sleep is a significant factor in motor vehicle crashes experienced by teenage drivers. This report examines the hypothesis that a later high school start time may reduce crash rates by reducing the interference of school start time with the sleep needs of adolescents. We collected data from two jurisdictions, Forsyth County, North Carolina, and Fayette County, Kentucky, that changed to substantially later high school start times. We examined whether these changes were accompanied by a drop in crash rates among 16- and 17-year-old drivers. Monthly time series were compiled corresponding to the overall rate of crashes on school days, adjusted for the 16- and 17-year-old population. An intervention time series analysis was applied to determine whether the change in school start time was accompanied by a downward shift in the level of the crash rate series. To control for possible confounding factors, comparable statistics were also compiled, using the same analyses, for several other counties where there was no change in school start times. For Forsyth County, North Carolina, there was a decrease in crash rates corresponding to the change in school start time, though the statistical significance of the effect is only moderate (one-sided p-value = .04). No corresponding effect was observed for three comparable counties of North Carolina. For Fayette County, Kentucky, there was no evidence of a statistically significant change in crash rates. Because of anomalous data in the one available comparable county, we were unable to derive meaningful results for a comparison county in Kentucky. We conclude that there is mild evidence that the change in school start times in Forsyth County, North Carolina, had a beneficial effect, but there is no corresponding evidence for Fayette County, Kentucky. |
| Rosap ID | dot:1989 |
| Rosap URL | https://rosap.ntl.bts.gov/view/dot/1989 |
| TRT Terms | Teenage drivers; Sleep; Traffic safety; Traffic crashes; Crash analysis; High schools; Hypothesis testing; Data collection |
| General Subjects | Teenage drivers; young drivers; adolescent drivers; fatigue; drowsy driving; high school start time |
| Geographical Coverage |
North Carolina; Kentucky |
| Report Number | DOT HS 812 221 |
| Availability | NHTSA - Behavioral Safety Research |
| Resource type | Tech Report |
| URL | https://ntlrepository.blob.core.windows.net/lib/60000/60900/60979/812221-HighSchoolStartTimesAndTeenDriverCrashes.pdf |
| Format | |
| Database | NTL Digital Repository |