I’ve heard for years that more people get into accidents after the clocks change in the spring. Is there anything you can do about it? – Barry, Edmonton
With the switch to daylight savings time on March 10, your chances of getting into a crash might spring forward due to the loss of sleep.
“There are a number of studies around the [United States] and Canada that say for the first week after the change to daylight saving [DST], there can be around a 7 per cent increase in fatalities,” Rick Lang, manager of driver education for the Alberta Motor Association (AMA).
If crashes do increase, the biggest reason is probably that we’re suddenly sleepier.
Most of us get about 40 minutes less sleep the night after the switch, which can make us dangerously drowsy. Especially if we’re already getting less than 7 or 8 hours a night.
“It’s only moving the time by one hour, but if you’re already getting just enough sleep, that can push a lot of people over the threshold,” Smith said.
Gaining an hour in the fall didn’t cause a significant increase or decrease in accidents, Smith said.
So, can’t you just go to bed an hour early Sunday night?
“That doesn’t really work, because your body has an internal clock, and when you’re disrupting that, you either disrupt the amount of sleep you’re getting or the quality of sleep,” said Jeffrey Hickman, a researcher with the Virginia Tech Transportation Institute. “To prevent that, you would have to go to bed 15 minutes earlier, in increments, every night, starting a week before — and nobody does that.”
The effect, similar to jet lag, can last a few days until you get used to it, or until you catch up on sleep the following weekend.
“A lot of the consequences are very similar to distracted driving, except you experience them your entire drive and not just when you’re texting,” Hickman said.
Spring ahead safely
There’s another theory for a rise in crashes. The sun rises an hour later, so it’s darker than you might be used to during your morning commute, and thus harder to see other cars, pedestrians and cyclists.
“You should be driving with your headlights on; daytime running lights are not enough,” the AMA’s Lang said. “And you should be watching out for pedestrians and kids.”
In studies trying to link DST to crashes over the years, the findings have varied. Some studies show that over the long run, DST might actually reduce crashes because there’s more light later in the evening, when drivers are less alert.
The U.S. National Highway Transportation Safety Administration said that from 2012-2017, there were only three more crashes nationwide on the Monday after DST (428 crashes) compared to an average Monday (425 crashes).
In a 2016 study, Austin Smith, assistant professor of economics at Miami University in Oxford, Ohio, looked at fatal-crash data across the continental United States from 2002 to 2011 after the time changes. Smith estimated that the switch to DST caused a 5 to 6 per cent increase during that entire week – or about 30 extra deaths a year.
Transport Canada said it doesn’t have data on crashes around DST. In 2015, Manitoba Public Insurance (MPI) reported a 20 per cent spike in crashes on the Monday after daylight savings the year before, but MPI now says the cause was actually a blizzard that day.
If the switch affects you, caffeine could help, but only for the first two or three days before the effects wear off, said Virginia Tech’s Hickman.
Otherwise, you just need to be aware that you might be a daylight savings zombie for up to a week.
Watch out for signs – such as yawning, seat fidgeting, difficulty staying in your lane, difficulty maintaining speed and delayed reactions – that you may be too tired to drive.
“People are really good at understanding that they’re tired, but most people say they can power through it,” Hickman said.
And if you’re tired on a longer drive, it helps to take a break and get out of your car.
“It doesn’t have to be a nap; just stop driving,” Hickman said. “You might be able to make it another 30 minutes or an hour.”
And even if you’re well-rested, other drivers might not be.
“Daylight savings doesn’t really affect my body, but I watch out for the other guys,” the AMA’s Lang said.
Have a driving question? Send it to email@example.com. Canada’s a big place, so let us know where you are so we can find the answer for your city and province.
Stay on top of all our Drive stories. We have a Drive newsletter covering car reviews, innovative new cars and the ups and downs of everyday driving. Sign up for the weekly Drive newsletter, delivered to your inbox for free. Follow us on Instagram, @globedrive.