Changing the clock and navigating between daylight saving and winter time may have bigger consequences than just losing an alarm, as a new study finds that it makes drivers drive more dangerously.
Researchers at the University of Padua in Italy and the University of Surrey have discovered that DST disrupts people’s sleep-wake cycle.
The impact of daylight saving time on driving
They tested the driving capability of 23 Italian drivers before and after the introduction of Spring Daylight Saving Time, and found that they were exposed to further risks as a result of this change.
Their reaction times and ability to read situations on the road were also compromised after clock loss.
This is thought to result from sleep deprivation and disruptions of their daily rhythms – the internal process that regulates the sleep-wake cycle and other rhythmic functions.
Professor Sarah Montaise of the University of Surrey said: “It is known that disturbing our sleep and circadian rhythm due to daylight saving time increase health risks such as heart attacks, but what is unknown is the risk it can cause on our roads, due to its impact on driver behaviour.
“The results from our study will show that there is no place for daylight saving time in today’s world, where the negatives far outweigh the positives.”
To get their results published in iScience, study participants were asked to drive a 7-mile-1.9-kilometer track on a driving simulator.
This included both rural and urban roads, and provided drivers with different scenarios to test whether they would face unnecessary hazards or exhibit dangerous behaviour.
In one case, participants found themselves behind a vehicle on a long straight road with a continuous central line to see if any of them would try to overtake.
The same situation was only displayed with a cyclist, and the driver also had to prove that he could safely exit the highway.
The experimental group took over these tasks before and after moving to daylight saving time, which included clocks going back an hour.
A group of 22 drivers took the tests twice, but those two occasions were in the two weeks leading up to daylight saving time.
Prior to Daylight Saving Time, experimental and control groups were found to have shown similar behavior, with only 9% opting to overtake the car.
However, after the move, 39% of the pilot group outperformed the flagship, while the control group maintained safer behaviors.
This suggests that those in the experimental group were more likely to engage in risky behavior, such as overtaking, after changing hours.
When facing a cyclist, most participants overtake the experiment and control regardless of whether their time zone has changed or not.
The disturbance in their physical clock became apparent by the distance each group left as the cyclist passed.