School start time change and motor vehicles crashes

Bin-Hasan, S., Kapur, K., Rakesh, K., & Owens, J. (2020). School start time change and motor vehicles crashes in adolescent drivers. Journal of Clinical Sleep Medicine. Advance online publication. https://doi.org/10.5664/jcsm.8208

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Abstract

Study Objectives

The aim of this study was to examine the association between a 50 minute delay (7:20am to 8:10am) in high school start times in Fairfax County (FC) Virginia (VA) and changes in rates of adolescent motor vehicle crashes. Crash rates in FC were also compared to those in the rest of the state during the same time period.

 

Methods

VA Department of Motor Vehicles crash data in 16-18 year old drivers between September and June of each year in FC versus the rest of the state were compared in the combined two year periods preceding (2013-14 and 2014-15; T1) and following (2015-16 and 2016-17; T2) school start time change in the fall of 2015.

 

Results

The crash rate per 1000 in 16-18 year old licensed drivers in FC during T1 was significantly higher compared to T2, 31.63 vs 29.59 accidents per 1000 (95% CI, 1.0-1.14, OR 1.07, P=0.03). In contrast, adolescent crash rates in the rest of Virginia were not statistically significantly different at T1 vs T2. With regards to subtypes of crashes, there was a trend towards significance in distraction-related crashes per 1000 in FC at T1 compared to T2 at 7.01 vs 6.13 (95% CI, 0.99-1.31, OR 1.14, P=0.05), but were not significantly different in the remainder of the state.

 

Conclusions

The results of this study suggest that school start time delay is associated with decreased adolescent motor vehicle crash risk, with significant implications for public health and safety.

 

Keywords

Motor vehicle crashes; adolescent sleep; school start time change