Does Changing the Clock Cause an Increase of Car Accidents?

Few people complain about turning their clocks back an hour each fall at the end of Daylight Savings Time. An extra hour of sleep is a gift to anyone who hurries through their days to meet daily responsibilities to work and family. But many neglect to think about how the time change could be a contributing factor when it comes to serious crashes.

In general, “falling back” each autumn doesn’t cause as much of a problem for drivers as losing an hour of sleep by “springing forward.” But don’t be fooled – the fall time change can also be difficult for motorists. It gets darker earlier in the day, so the light conditions during the late afternoon/early evening commute may make it harder to see other vehicles, pedestrians or obstructions on the road.

There are behavioral shifts that may arise at the end of Daylight Savings Time that could contribute to deadly crashes in the fall, experts say. A 2001 University of California study found there is a marked increase in the number of automobile accidents in the immediate days following a fall time change, particularly on the Sunday after the shift. Researchers suggest that people anticipate a longer evening on that Sunday, which could mean a rise in more late night behavior, such as drinking alcohol and staying awake long past a normal bedtime.

Fatigue can wreak havoc on a person’s driving abilities. To drive safely, individuals must coordinate both mental and motor skills so that they are able to stay alert, react quickly and make good judgment calls on the road. According to the Centers for Disease Control and Prevention, the average adult needs seven to nine hours of sleep per night to perform optimally. Although individual needs vary, the National Highway Traffic Safety Administration reports that those who operate on a habitual sleep deficit – even if it’s just by one or two hours each night – are more likely to suffer from chronic sleepiness and are at an increased risk for motor vehicle accidents, either from falling asleep at the wheel or by making fatigue-related errors.

Sleep experts say our internal body clock, called circadian rhythms, function on a slightly longer than 24-hour schedule. Our bodies, by design, don’t have to struggle as much to adapt to more rest. But disrupting the natural sleep-wake cycle by losing an hour each spring can be unsettling and contribute to reduced performance, both in daily life and behind the wheel.

Daylight Savings Time only makes the problem worse. Researchers have found that in the days after the spring time change, there is a rise in the number of car accidents, heart attacks and workplace injuries, according to the Huffington Post. Another study found that in the first five days following a spring time change, there is an increase in the likelihood of traffic accidents, perhaps because the lack of quality sleep causes periods of “microsleeps” that lead to lapses in attentiveness while driving.

Add to that another far-reaching problem that is already plaguing the country – Americans are exhausted. A 2011 survey from the National Sleep Foundation found that 43 percent of Americans between the ages of 13 and 64 reported they rarely or never get a good night’s sleep on weeknights. More than half said they experienced some sort of problem that kept them from sleeping soundly and waking up refreshed.

To reduce the effect of the time change on your driving in the spring, sleep scholars suggest adjusting your bedtime by a few minutes each night as you approach the change. Sleep adjustments are less important in the fall, but it is crucial for you to be aware of how the new driving conditions – such as sunshine glare during the morning drive and dim light at dusk – could impact your experience on the roads.

Above all, you should never drive if you know you are too exhausted to be safe. Make every effort to be well rested before you hit the road and give yourself plenty of time to get to your destination without rushing or making poor decisions. Gaining or losing an hour of sleep may not seem like enough of a shift to make a difference in your driving abilities, but it’s certainly not worth it to question the experts.