Avoid Night Owls on Your Morning Commute

This article was originally posted at RealClearScience.

There are certain types of drivers that we should always strive to avoid. The speeders, the chronic lane changers, the texters, and the elderly — who spend most of their time driving 40 mph in the fast lane with their left turn signal flashing — are easy enough to identify. But, there’s another group of drivers that also poses a threat, but is much harder to recognize: Night owls on the morning commute.

In a new study in Accident Analysis & Prevention, researchers analyzed 25 female volunteers who were selected based on their responses to a chronotype survey. Thirteen of the volunteers were early birds, and twelve of them were night owls. They were asked to complete a simulated driving test at 8 am and 8 pm. The track was incredibly boring, essentially a giant oval, and was purposefully selected to make the task as tedious as possible. The volunteers had to follow a green line down the middle of the road at 60 mph, constantly adjusting their driving to account for slight imperfections in the road. In each session, the volunteers had to drive for about 1 hour. How did they do?

A couple of the drivers crashed their cars, so maybe the task was too difficult for them. The rest, however, provided an interesting data set: Night owls did not perform as well as early birds in the morning commute. (See graph.)

As shown above, night owls had a hard time driving straight, and they performed progressively worse as time went by — despite the fact that both early birds and night owls had similar levels of sleep the previous night. On the other hand, the early birds did just fine, both at 8 am and at 8 pm.

For you night owls, perhaps this study could be used to get your boss to allow you to clock in at work later in the morning. After all, you don’t want to be a hazard to other drivers.

Source: Correa A, Molina E, Sanabria D. “Effects of chronotype and time of day on the vigilance decrement during simulated driving.” Accident Analysis & Prevention 67: 113-118 (2014).