Every March, we are told to “spring forward,” set the clocks ahead, lose an hour of sleep, drink an extra cup of coffee in the morning, and move on as if it were no big deal. Many people can adjust to this seemingly minor inconvenience; however, on our roads, that one-hour shift is anything but minor.
Year after year, research shows that the days following the start of Daylight Saving Time (DST) are more dangerous for drivers, and our Georgia roadways are no exception. Both crash rates and fatal crashes increase significantly. While the reasons are not always due to someone rushing out the door on a Monday morning, the pattern is consistent enough that traffic safety experts, sleep researchers, and public health professionals have been flagging and tracking the data for decades.
This is not about being dramatic or anti-DST for its own sake; it is about understanding how sleep, light, and human biology intersect with real-world driving behavior and why those factors matter when thousands of cars share the road, as well as how we can proactively and mindfully make changes to increase everyone’s safety.
The Pattern We Keep Seeing: Crashes Rise After Spring DST
Multiple large-scale studies have examined what happens on U.S. roads immediately after clocks change in the spring. The conclusion is remarkably consistent: the risk of motor vehicle crashes increases, particularly in the first week after the change.
One of the most frequently cited studies examined 732,000 accidents in nationwide crash data spanning more than two decades. Researchers found that fatal car crashes increased by roughly 6 percent in the week following the spring DST transition. That may sound small until you translate it into real-world impact: an estimated 28 additional traffic deaths each year, directly tied to the time change.
In Varughese, Jacob, and Richard P. Allen’s “Fatal Accidents Following Changes in Daylight Saving Time: The American Experience,” it was reported that fatal motor vehicle crashes increased immediately after the spring transition, with a pronounced spike on the Monday after clocks move forward. Other studies using different datasets and timeframes have found similar effects, and in some cases even larger ones. An analysis of U.S. fatal crash data from 2010 to 2019 showed an approximately 12 percent increase in fatal crashes involving vehicle occupants in the weeks following the spring shift.
What’s important here is not just one study or one year of data, but rather the consistency of the finding across different researchers, time periods, and methodologies.
Why One Hour Makes Such a Big Difference
At first glance, losing a single hour of sleep does not seem like a big deal. After all, many people lose more than that by staying up late on a weekend. However, the DST shift is different, and there are two main reasons it affects crash risk so reliably.
1. Sleep Loss and Circadian Disruption
The most significant factor is sleep.
When clocks spring forward, most people don’t actually go to bed an hour earlier. Instead, they wake up an hour earlier according to their internal body clock. That results in acute sleep deprivation — and more importantly, circadian misalignment.
Our bodies run on internal clocks that regulate alertness, reaction time, and decision-making. When those clocks are suddenly pushed out of sync, even by just an hour, performance suffers. Researchers often describe the spring DST shift as a form of “mini jet lag.” You haven’t traveled anywhere, but your body reacts as if you have.
A study conducted by the University of Colorado found that the biannual time switch is linked to increased health risks beyond traffic safety, including more workplace injuries, sleep disturbances, and higher rates of serious cardiovascular events. Researchers have linked the spring DST change to increases in heart attacks and strokes, particularly in the days immediately following the shift. As with the rise in car accidents, these health effects are believed to stem from circadian rhythm disruption and sleep deprivation caused by the sudden loss of sleep.
When you zoom out, a clear pattern emerges. Abrupt shifts in our internal clocks have measurable consequences across multiple systems. Driving is one of the most visible and immediate ways these consequences show up, but it is far from the only one.
This disruption can last for several days, sometimes longer. Drivers may experience:
- Slower reaction times
- Reduced attention and vigilance
- Poorer judgment and risk assessment
- Increased drowsiness, especially in the morning
All of these factors directly affect driving safety. Sleep deprivation has long been recognized as a serious crash risk, and in many ways, drowsy driving mirrors impaired driving. Both reduce a driver’s ability to process information, respond to hazards, and make split-second decisions. Even modest sleep loss can significantly increase the likelihood of a mistake behind the wheel.
2. Darker Morning Commutes
DST doesn’t just change the clock; it alters the relationship between clock time and sunlight. After the spring shift, mornings are suddenly darker. Sunrise occurs later by the clock, which means many people are commuting to work or school in lower light than they were just days earlier.
In Georgia, this timing coincides with peak morning travel, when commuters funnel onto major interstates, state routes, and two-lane rural roads to get to work or school. Morning rush hour is already one of the most dangerous times of day, with school buses on the road, traffic volume concentrated, and many drivers in a hurry. In metro Atlanta and surrounding counties, the risk is amplified by long commute times and heavily traveled corridors such as I-75, I-20, and I-675. When fatigue and lingering darkness are added to the mix, the danger increases even further.
For many drivers across the state, traveling a mix of interstate highways and rural roads with limited lighting makes visibility issues especially dangerous in the early spring, when fog and rain are common. Reduced morning light can:
- Make it harder to see road hazards
- Increase glare from headlights, especially on wet roads
- Reduce visibility of pedestrians, cyclists, and other vehicles
Geography Matters Too
Another important finding is that the effects of DST are not evenly distributed across the country. Research shows that crash rates tend to rise more in the western portions of time zones, where the sun rises later relative to clock time. Because these areas already experience less sleep than their eastern counterparts, the spring DST shift compounds the problem. As a result, states such as Texas and Utah saw an 8 percent increase in fatal accidents, with drivers averaging about 19 minutes less sleep than those in the eastern portions of the same time zone (Ries).
In those areas, the DST shift can push sunrise even deeper into the morning commute. That means darker conditions for longer periods, along with the same sleep disruption experienced everywhere else.
What Can Be Done to Reduce the Risk?
Although the DST shift is currently integrated into our calendar, its potential risks can still be effectively managed by making these minor adjustments to our lives as we approach the time change.
Adjust Sleep Ahead of Time
Ease into the time change by gradually moving your bedtime 15 to 20 minutes earlier over several days before the shift. This approach can help reduce sleep deprivation and make the transition smoother and less dramatic.
Slow Down and Stay Alert
For drivers, especially during the first week after DST:
- Be extra cautious during morning commutes
- Watch for signs of drowsiness
- Avoid distractions and aggressive driving
- Give yourself extra time so you are not feeling rushed
Final Thoughts
For Georgia drivers, the spring Daylight Saving Time shift arrives just as traffic volumes begin to rise with better weather, school schedules, and longer daylight hours. The combination of these events makes the first week after the time change a critical period for heightened awareness and caution on all our roadways.
Since we know that every year, the start of DST brings a predictable pattern of increased deaths from crashes, let us all remain proactive to protect the lives of everyone in our communities and beyond.
If you or a loved one has been in an accident and is seeking a local Georgia attorney, call us at 866-982-5295 or visit our Georgia car accident attorney page.
Sources
‘Spring Forward’ to Daylight Saving Time Brings Increase in Fatal Car Crashes.” ScienceDaily, 30 Apr. 2015, www.sciencedaily.com/releases/2015/04/150430104017.htm.
Varughese, Jacob, and Richard P. Allen. “Fatal Accidents Following Changes in Daylight Saving Time: The American Experience.” Sleep, vol. 24, no. 4, 2001, pp. 409–411.
Ries, Julia. “The Number of Fatal Car Accidents Spikes After Daylight Saving Time.” Healthline, 6 Mar. 2020, http://healthline.com/health-news/daylight-saving-can-make-driving-less-safe.
