Daylight saving time and car accidents – what’s the connection?

Chances are good that your work day felt a little bit harder today than on most Mondays. Why is that? Most likely, it was due to the one-hour time change associated with the beginning of daylight saving time. When we “sprang forward” over the weekend, Americans collectively lost an hour of sleep.

While shifting your internal clock by an hour can disrupt your body on its own, the effect is even worse among those who are chronically sleep-deprived (which most Americans are). In the days following the start of DST, workplace productivity goes down, workplace injury rates go up and your risk of car accidents increases.

Several prominent studies have examined car accident data spanning two decades or more. These studies revealed that on this day each year (the Monday after DST starts), there is a “very small, but significant, increase in road deaths,” according to news sources.

The DST effect is not uniform across all countries. It seems to be especially prominent here in the United States, most likely because of our already poor sleeping habits.

There are at least two reasons why traffic accidents might increase this week. First, there is the sleep deprivation factor. Drivers are not as alert and their reaction times may be slower. The other reason is the shift in when sunrise and sunset occur. Those of us used to driving home in the dark may now be heading home at dusk, leading to sun blindness when the sun is at a certain point on the horizon. This can make it very difficult to see pedestrians, bicyclists and other cars.

If you find yourself especially tired this week, remember that DST may be interrupting your body’s natural rhythm. And until you can adjust to the new time, please be especially cautious behind the wheel.