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This study analyzed the impact of permanent daylight saving time (DST) on school commutes across 14 U.S. states, finding that permanent DST would create approximately 2 billion additional dark-morning commutes annually for K-12 students compared to the current system. In Washington State alone, permanent DST would add 35 million child-days of pre-sunrise travel despite current conditions requiring none. Analysis of Seattle traffic data revealed that pedestrian crash odds were 143% higher during dark morning conditions, suggesting permanent DST would substantially increase children's exposure to elevated accident risk.
Why it matters
This research provides quantitative evidence relevant to the ongoing U.S. debate over adopting permanent daylight saving time, directly addressing child safety concerns that have not been previously measured at scale. The findings suggest that permanent DST legislation could significantly increase pedestrian danger for millions of schoolchildren during morning commutes, particularly during winter months.
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⚠️ Preprint – Noch nicht peer-reviewed
Dieser Artikel wurde noch nicht von unabhängigen Experten begutachtet. Die Ergebnisse sind vorläufig und sollten mit Vorsicht interpretiert werden.
The U.S. House’s approval of the Sunshine Protection Act has revived the debate over permanent daylight saving time (DST) versus permanent standard time (ST). Health and sleep organizations favor permanent ST because it benefits health, especially for children with rigid school schedules. Further, permanent DST would push school start times to before sunrise in many regions, leading to dark-morning commutes. However, the safety consequences of this shift remain unquantified. Using real school start times for 14 states that have enacted permanent DST legislation, together with local sunrise time, we counted the school days on which students must leave home before sunrise under permanent ST, the current system, and permanent DST. In Washington State, where schools start on average at 08:27, neither permanent ST nor the current system requires any pre-sunrise departure, whereas permanent DST would for most of the winter. Using real school start-time data, permanent DST would add about 35 million child-days of pre-sunrise travel in Washington alone relative to the current system, with similar patterns across the other 13 states. Extrapolated to all U.S. public schools and assuming an 8:00 departure, permanent DST would generate more than 2 billion additional dark-morning commutes each year relative to the current system. Finally, analyzing Seattle traffic collisions, we found that the odds that a crash involved a pedestrian were 143% higher on dark mornings (adjusted odds ratio 2.4). Permanent DST would therefore expose many more children, on many more days, to elevated pedestrian-crash risk, evidence that deserves consideration as the United States chooses a time standard.
Source: Over a Billion More Dark Morning School Commutes for K-12 Children under the Sunshine Protection Act