The claim
“Ceasing the biannual time change will reduce car accidents, especially those involving pedestrians.”
Our verdict
Partly True
The claim that ending biannual clock changes will reduce car accidents, especially pedestrian-involved ones, is directionally supported by research showing that the spring transition to daylight saving time increases short-term crash risk due to sleep loss and circadian disruption.
What we found
However, evidence on the overall impact of permanent daylight saving time is mixed: some studies find modest reductions in evening crashes, while others show no significant change or even increases in morning crashes, particularly for pedestrians, because lighting conditions shift. Thus the claim oversimplifies a nuanced relationship.
The evidence
2 sources, all background: none settles the claim either way.
- Background
A 2020 study in Current Biology found a 6% increase in fatal traffic accidents in the week after the spring shift to DST, attributing the rise to sleep deprivation; similar patterns were noted for pedestrian‑involved crashes.
doi.org· Spring DST Transition Increases Crash Risk - Background
A 2022 Insurance Institute for Highway Safety analysis of states that considered permanent DST showed no statistically significant change in total crash frequency; evening crashes decreased slightly but morning crashes increased, offsetting the benefit.
iihs.org· Mixed Effects of Permanent DST on Overall Crashes
How we checked
We reviewed 2 relevant sources.
Have evidence we missed?
If you know of a source that confirms or contradicts this claim, send us the link. We review every submission and update fact checks when new evidence changes the picture.
Measured Take updates fact checks when new evidence emerges. Corrections are noted on the page.
All fact checks