Alert: Daylight Switch Increases Crash Risk

Annual "Fall Back" means sun glare for the AM commute, darkness for the PM commute, and potential for drowsy drivers.

Traffic Safety

DENVER (Oct. 29, 2020) -  The end of Daylight Saving Time brings with it much more than just an extra hour of sleep this coming Sunday. In fact, the seasonal shift in our sleep patterns, combined with new lighting conditions during morning and evening commutes, significantly increase the risk of a car crash for several weeks following the switchover. 

"Shorter days mean many of us will drive more in the dark, especially 9-5 commuters," said AAA Colorado spokesman Skyler McKinley. "That's a problem, in part, because we've gotten used to nearly eight months of daylight during the evening commute. That all changes now. Sunset is one of the most challenging times to drive, as your eyes must frequently adjust to increasing darkness."

AAA recommends that motorists prepare for night driving by reducing speed and increasing following distances, ensuring that headlights and taillights are operational, and getting plenty of rest before driving.

Behavioral Changes Increase Risk
Paradoxically, even though we should be gaining an hour of sleep, the disruption to our sleep patterns helps drive fatigue-related crashes. 

Researchers at Stanford University and Johns Hopkins University, in partnership with the Insurance Bureau of British Columbia, found that changes in motorist behavior as Daylight Saving Time ends fundamentally increase crashes following the time change. Why? Initially, people stay up later than usual, anticipating they'll get an extra hour of sleep, and end up driving drowsy.

The broader disruption to our body's sleep/wake cycle and circadian rhythm, meanwhile, can last up to two weeks. 

Sleep-deprived drivers cause more than 6,400 deaths and 50,000 debilitating injuries on American roadways each year, per the National Sleep Foundation. 

Symptoms of drowsy driving can include trouble keeping eyes open, drifting from lanes, or not remembering the last few miles driven. Alarmingly, however, more than half of drivers involved in fatigue-related crashes experienced no symptoms before falling asleep behind the wheel.

"Your body can't always warn you that you're too tired to drive," McKinley said. "The only safe bet is making sure you get enough sleep."

Research from the 2016 AAA Foundation for Traffic Safety report on sleep deprivation and motor vehicle crashes shows that missing just one to two hours of sleep in a 24-hour period nearly doubles crash risk. All told, drowsy driving contributes to more than one in five fatal crashes on U.S. roadways each year. 

Additional data from the 2017 AAA Traffic Safety Culture Index show that more than 95 percent of motorists consider drowsy driving "completely unacceptable" – and yet, three in ten Americans admitted to driving when they were too tired to keep their eyes open at least once in the past month. 

"America's problems with drowsy driving stem from this 'Do as I say, not as I do' mindset," McKinley said. "The end of Daylight Saving Time gives us a good reason to review our driving habits, especially because traffic death rates are three times greater at night than during the day. Get enough rest, and be mindful of everyone on the roads – other drivers, bicyclists, and pedestrians. The pandemic demands that we do everything we can to protect our first responders and maintain hospital capacity by preventing crashes."

AAA Colorado offers the following tips to help drivers avoid potential crashes:

  • Rest up. Your crash risk goes way up whenever you get fewer than seven hours of sleep. If you do begin to feel drowsy while driving, pull over immediately and rest or call a family member or friend for assistance.
  • Be prepared for morning/afternoon sun glare. Sun glare in the morning or late afternoon can cause temporary blindness. To reduce the glare, wear high-quality sunglasses and use your car's sun visors. Use of the night setting on rear-view mirrors can reduce glare from headlights approaching from the rear. 
  • Care for your car. Keep headlights, tail lights, signal lights, and windows (inside and out) clean.
  • Ensure headlights are properly aimed. Misaimed headlights blind other drivers and reduce visibility. 
  • Keep headlights on low beams when following another vehicle, so other drivers are not blinded. Turn off your high beams when there's traffic in the oncoming lane. 
  • Reduce your speed and increase your following distances. It is more difficult to judge other vehicles' speeds and distances at night.
  • Be mindful of pedestrians and crosswalks. Yield the right of way to pedestrians in crosswalks and do not pass vehicles stopped at crosswalks.  

AAA Tips for Pedestrians and Bicyclists

  • Cross only at intersections. Look left, right, and left again and only cross when it is clear. Cross at the corner – not in the middle of the street or between parked cars. 
  • Avoid walking in and near traffic when there are no sidewalks or crosswalks. If you have to walk on a road that does not have sidewalks, walk facing traffic
  • Evaluate the distance and speed of oncoming traffic before you step out into the street
  • Wear bright colors or reflective clothing if you are walking or biking near traffic at night. Carry a flashlight when walking in the dark.
  • Avoid distracted walking and biking, including looking at your phone, wearing headphones, or listening to music. 
  • Bicycle lights are a must-have item for safe night riding, especially during the winter months when it gets dark earlier. 

About AAA – The Auto Club Group

AAA Colorado is a proud part of The Auto Club Group (ACG), the second-largest AAA club in North America with more than 14 million members across 14 U.S. states, the province of Quebec and two U.S. territories. ACG and its affiliates provide members with roadside assistance, insurance products, banking and financial services, travel offerings and more. ACG belongs to the national AAA federation with more than 60 million members in the United States and Canada. AAA’s mission is to protect and advance freedom of mobility and improve traffic safety. For more information, get the AAA Mobile app, visit, and follow us on Facebook, Twitter and LinkedIn. Learn more.