“Carcolepsy”: The instant feeling of being sleepy during long drives

Whether on a road trip with my friends or taking a long Uber ride back home, I always seem to get instantly sleepy the moment the car pulls off. For many years, I assumed it was just from being tired from the day, but I discovered that this condition has a name: Carcolepsy.  

Carcolepsy is defined as “a condition in which a passenger falls asleep as soon as the car starts moving.” Although not officially a word, the cause of carcolepsy has eluded thousands of people who can’t seem to stay awake once they get into a moving vehicle. While this issue may be helpful for bored passengers, it can prove irritating at best, and fatal at worst, for drivers around the world.

Car rides can be somewhat relaxing.

Although the feeling of your skull bouncing off the back of your headrest may not qualify as conventionally comfortable, the passing lights and gentle hum of the engine mimic relaxing white noise.  If you’re sitting in the passenger seat or backseat, your only job is to sit back, relax and let the ride take you to dreamland. If you’re in the front seat, even when you’re completely focused on the road, every gentle sensation can trigger feelings of being rocked to sleep. Combine that with the murmur of the radio or an especially dull NPR podcast, and it’s hard to imagine staying awake for very long.

Car rides are tedious and cause “highway hypnosis.’

One scientific explanation of why people get tired after long stints of being in a car is known as “highway hypnosis.”

In “Traffic and Transport Psychology: Theory and Applications” by Geoffrey Underwood, the author defines highway hypnosis as a “trance-like state that one can experience from either driving or riding in a car for a long period of time.” Although his theory focuses around the general feeling of tiredness, it has nothing to do with being physically fatigued, although the two go hand and hand.  

Repetition and high predictability are much of what goes into highway hypnosis. Since long car rides mostly involve similar factors –things like long monotonous roads, yellow and white painted lines and bright street lights – it causes our attention span to take a plunge.

Because we’re so used to seeing the same things over and over again, the entire process begins to feel almost autonomous.  Underwood explains this is what causes a state of sleepiness, not total fatigue.

Car rides maintain a consistent level of “white noise”

A big reason why cars can create a great place for people to sleep is the presence of white noise.  Colin Lecher, of Popular Science, defines white noise as “a consistent noise that comes out evenly across all hearable frequencies.” White noise is also used as a common solution to help people who suffer from sleeping problems.

For people who suffer sleeping disorders, white noise can covers all distracting sounds that might wake up light sleepers. According to Lecher, “when a noise wakes you up in the night, it’s not the noise itself that wakes you up, but the sudden change or inconsistencies in noise that jar you.”

Long periods of driving constantly emits white noise. From the engine, to the sound of driving along the open road –cars create their own world full of white noise, that is the ultimate lullaby for every passenger.

Final Thoughts

To all carcolepsy sufferers, you are not alone. Millions of people every year experience this same feeling. To all the drivers, passengers now have an excuse for leaving you alone to go to dreamland. Stay cautious, stay alert and let your friends/family experience the beauty of car sleep and maybe one day, you’ll be able to be a passenger who drifts off into dreamland at the snap of the finger.