Highway hypnosis: Causes and prevention

HOUSTON – Alyssa Oullette said the feeling can be a little scary.

"Just driving the same path every single day and sometimes I'll just show up and I don't remember getting here," she said.

She's describing a phenomenon known as highway hypnosis. To understand what it is, you need to know what it is not. It's not drowsy driving.

"That is essentially where you're losing a lot of your consciousness and sort of fading and not reacting things, and not seeing things and then fall asleep and boom there's a crash," Wayne State University professor Randall Commissaris explained.

And it's not distracted driving. That's people eating, grooming or texting while driving.

"It's a tremendous threat to safety. Probably 30,000 people a year are involved in crashes with a distracted driver and well over 3,000 a year are killed by a distracted driver," Commissaris said.

Highway hypnosis occurs when you're paying attention to your driving, but not really.

"I'm not consciously distracted. I'm not drugged. I'm not drunk. All my facilities are actually engaged in my driving at that time, it's just that I don't remember any of it," Commissaris said.

Commissaris uses a driving simulator and willing volunteers to study driving. He said, in a hypnotic state, drivers really are aware and paying attention, even if they don't remember doing it.

"You're so in your routine, you're just driving, driving, driving. You're not looking for exits like you would if it's a new place you've never been before. It's just kind of automated," Oullette said.

But Commisaris said when you have those black holes of memory while driving, it's nothing to worry about.

"Probably not a real safety hazard in the sense that they were awake. They were not drowsy. They were responding and reacting appropriately all the time while they were driving," he said.

He said it's part of our defense against sensory overload. We keep the memory clear of information that we even unconsciously deem irrelevant.

To avoid highway hypnosis, Sgt. Erik Burse with the Texas Department of Public Safety suggests:

Changing up your regular driving routes frequently so they don't become routine.
Rest up before driving long distances.
If you are driving a long way by yourself, stop and take a break at least every hour and a half. If you're with another driver periodically trade off who gets behind the wheel.