Why Accidents Increase After Daylight Savings Switch

Was traffic noticeably slower on your morning commute these past couple of days? If so, blame daylight saving time. The “spring forward” is believed to cause a temporary spike in traffic incidents. A 1998 Canadian study found that auto accidents may increase as much as 17 percent immediately following the time change.

Media outlets tend to report a few theories on why accidents swell after the spring time change. Each seems reasonable at first glance:

• Drivers acclimated to commuting after the sun is already out may find themselves blinded by the sunrise or driving in the dark.


• More drowsy drivers are on the road after difficulty falling asleep at the regular time due to the spring forward.


• Some people recklessly rushed to work after forgetting to reset their alarm clocks and accidently oversleeping.

The authors of the Canadian study argue drowsy driving – rather than the other two factors – is why the frequency of accidents escalates after the time change. The study found the only significant increase in accidents occurred during the afternoon commute. That finding appears to rule out an early sunrise or forgetfulness as the reason for an increase in accidents.

Last week, the Sleep Education Blog shared some tips to better brace for the time change but not everyone spends days preparing for the hour of lost sleep. The blog also reported that well-intentioned evening types may still struggle because falling asleep even slightly earlier than normal may be difficult. It may take weeks, but most of the people who fall under either category will eventually adjust and become safer drivers once again.

The “fall back” in November appears to have the opposite effect of the “spring forward”: a sudden temporary decrease in accidents, according to the study. However, that may be quickly negated by Seasonal Affective Disorder (SAD), which tends flare up with the fall time change. SAD may lead to increased daytime sleepiness, which potentially, could mean more drowsy drivers on the roadways during the winter months.

Do you find yourself nodding off at the wheel on a regular basis? You may have a sleep disorder that prevents you from getting regular restful sleep. Schedule an appointment with a clinical sleep specialist and find out if you have sleep apnea or seek treatment for insomnia.

Photo by Slinkydragon