Skip to main content

Mobility Careful out there: The switch to Daylight Savings Time may spike driver fatigue

Because the sun rises an hour later after Daylight Savings Time kicks in, it’s darker than you might be used to during your morning commute.

Richard Vogel/The Associated Press

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).

Story continues below advertisement

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.

Story continues below advertisement

“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.

Story continues below advertisement

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.

While there have been calls to eliminate the annual change and stick either to daylight savings time or, like Saskatchewan, standard time, we’re stuck with it for now.

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.

Story continues below advertisement

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 globedrive@globeandmail.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.

Report an error Editorial code of conduct
Due to technical reasons, we have temporarily removed commenting from our articles. We hope to have this fixed soon. Thank you for your patience. If you are looking to give feedback on our new site, please send it along to feedback@globeandmail.com. If you want to write a letter to the editor, please forward to letters@globeandmail.com.

Welcome to The Globe and Mail’s comment community. This is a space where subscribers can engage with each other and Globe staff. Non-subscribers can read and sort comments but will not be able to engage with them in any way. Click here to subscribe.

If you would like to write a letter to the editor, please forward it to letters@globeandmail.com. Readers can also interact with The Globe on Facebook and Twitter .

Welcome to The Globe and Mail’s comment community. This is a space where subscribers can engage with each other and Globe staff. Non-subscribers can read and sort comments but will not be able to engage with them in any way. Click here to subscribe.

If you would like to write a letter to the editor, please forward it to letters@globeandmail.com. Readers can also interact with The Globe on Facebook and Twitter .

Welcome to The Globe and Mail’s comment community. This is a space where subscribers can engage with each other and Globe staff.

We aim to create a safe and valuable space for discussion and debate. That means:

  • Treat others as you wish to be treated
  • Criticize ideas, not people
  • Stay on topic
  • Avoid the use of toxic and offensive language
  • Flag bad behaviour

Comments that violate our community guidelines will be removed.

Read our community guidelines here

Discussion loading ...

Cannabis pro newsletter