If you’re feeling sleepy on your morning drive today, get used to it.
After the switch to daylight saving time (DST), your chances of getting into a crash spring forward for weeks because of drowsy driving, an expert said.
“We talk about losing an hour of sleep, but it’s actually much worse than that,” said Michael Antle, a professor of psychology and neuroscience at the University of Calgary. “[DST] is forcing you up and out of bed an hour before you’re ready for many weeks.”
Research shows an increase in fatal crashes on the “sleepy Monday” after DST begins.
A 2020 study by researchers at the University of Colorado found fatal crashes in the United States increased by 6 per cent, mainly in the morning, during the work week after the clocks moved ahead.
There wasn’t an increase in fatal crashes during the week after clocks moved an hour back to standard time (ST) in November.
The drowsiness can last longer than the first week. A 2024 study using driving simulators found drivers were still impaired four weeks after the spring change – and didn’t realize it. That’s largely because DST moves sunrise an hour later and puts us out of sync with our natural clocks, which rely on morning sunlight to wake us up, Antle said.
“Our circadian clock doesn’t like getting up before it’s ready,” he said.
The switch to DST is also linked to an increase in heart attacks and workplace injuries – but studies generally haven’t shown the same rise when we switch to standard time, Antle said.
Spring break?
British Columbia Premier David Eby announced last week that most of his province will remain on DST year-round after the March 8 change – joining Yukon, which made the move in 2020. Most of Saskatchewan doesn’t change its clocks - it has used central standard time year-round since 1966.
Alberta said it’s evaluating whether to adopt permanent DST. Ontario said it won’t make the change unless Quebec and New York do. So, why stick with DST and not standard time?
The move, which will create an extra hour of evening light during the winter months, means sunset in Vancouver on Dec. 21, the shortest day of the year, will move to 5:16 p.m. from 4:16 p.m.
That extra light “could” reduce pedestrian crashes around evening rush hour, Liam Butler, a spokesman for B.C.’s Ministry of the Attorney General, said in an email. “B.C. does not have statistics that isolate collision trends specifically related to daylight saving time.”
But it’s not clear whether evening crashes will drop or that year-round DST would make roads safer over all, said Lewis Smith, manager of national projects with the Canada Safety Council. “There’s currently very little research on places that have adopted permanent daylight saving time.”
Night shift?
A 2024 study by the U.S. Insurance Institute for Highway Safety found that fatal pedestrian and cyclist crashes drop in the weeks after clocks move forward in the spring and rise again after the fall time change.
But the real danger in the fall and winter is that days are shorter, which makes it harder for drivers to see pedestrians, Smith said.
In 2022, Toronto Police said pedestrian collisions that happen between 5 p.m. and 8 p.m. double in the months after the November time change – and collisions between 7 a.m. and 8 a.m. increase by 400 per cent.
Because permanent DST will mean darker mornings when kids are going to school, there could be an increase in morning crashes, even if evening crashes decrease, Smith said.
But the problem with permanent DST isn’t just that pedestrians will be harder to see – it’s that drivers could be dangerously tired in the morning for months, Antle said.
“You’re losing the acute harm of the abrupt change in the spring, but now you have months of people commuting while tired because they’re getting up before they’re ready,” he said.
With permanent DST, sunrise on Dec. 21 will be at 9:05 a.m. in Vancouver this year. It would be at 9:48 a.m. in Calgary and 8:48 a.m. in Toronto if Alberta and Ontario made the change.
“We think we’re going to like that extra hour of light in the evening after work, but every place that’s tried this has regretted it,” he said.
For example, the U.S. tried permanent DST in 1974 and went back to switching clocks after less than a year. Russia tried in 2011 and lasted three years.
Drivers should get off the road anytime they’re showing signs of drowsy driving – yawning, drifting in the lane or struggling to keep their eyes open, safety experts say. At night, dusk and dawn, you should slow down and watch carefully for pedestrians, especially at intersections.
But for traffic safety and overall health, the best solution would be permanent standard time because it’s more in tune with our natural clock, Antle said.
“It’s not about driving in the dark so much,” he said. “We have street lights. We have headlights on the car. [The real risk with DST] is being tired.”