Here's Why Your Commute Will Be Terrible This Monday

“I hate the Monday after daylight saving time begins,” said Sam Schwartz, former traffic commissioner of New York City. “I try not to have any meetings that morning.” Schwartz isn’t alone: Groggy commuters are equally perturbed by the time change—and their sleepiness leads to a jump in accidents.

A 1996 University of British Columbia study found that the "expected risk of accidents" on the Monday after the spring time change rose 17 percent, based an analysis of data from the U.S. National Highway Traffic Safety Administration. Other studies have found less extreme but still real traffic effects from the adjustment. A 2014 study out of the University of Colorado, Boulder, found daylight saving time “increases fatal crash risk by 5.4–7.6 percent.” And researchers in Finland who wrote a 2010 paper in the Journal of Environmental & Public Health, noted, “Those who are especially sensitive to circadian rhythm disruptions, such as patients suffering from seasonal affective disorder or bipolar disorder, may be more vulnerable to sudden changes in timing.”