Carcolepsy: Why Do We Get Sleepy in Cars?

Have you ever been driving down the highway and start to notice that you're feeling really relaxed, even sleepy? It turns out there are number of aspects of driving that can potentially conspire to lull our bodies into a potentially dangerous state of drowsiness.

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Sources:

[adriengriffon]

As an over-the-road truck driver, I can confirm the vibration thing. Sleeping in the sleeper of the truck is way easier with the engine running than when it's turned off, the vibration of the engine makes you nod right off.

[talos]

All reasons aside, I still find it absolutely ridiculous that I'm consciously doing something that could end in death, but my body is like nah go to sleep.

[rachelhansen]

I always thought that all those factors make it almost "womb like"-- gentle noise and movement. Parents of young kids often find that they fall asleep in cars, and I always figured this was why.

[kenzito]

So in a car:

Noise (humming)
Vibration (shaking)
Temperature (warming)

Add them all together and you get a womb on wheels.

[veryberry]

I had one instance, several years back, where being exhausted in the car almost killed me. It's a long story, but in the end, I was so tired that I didn't even realize I had fallen asleep. I've never had that happen before. One of those instances had me jerking awake just as I was cruising at 70 toward a guard rail at a highway exit split. Thank god it wasn't into oncoming traffic. There was a reason I wasn't able to pull off onto the side of the road to nap, but after that experience I realized no reason is actually good enough to risk your life. I won't be repeating that experience!

[Kevin_Street]

When I was a child I slept far more deeply on car rides than in my bed. I have lots of confused memories of dreams mingled together with classical music from the radio and random cityscape going by that must have been from when I briefly opened my eyes then closed them again. I think I'd wake up when the car turned then go back to sleep on the straightaways.

[DeeDeeCatMom]

Yup, I totally have this...Even after 10 minutes of driving I can feel my panic self trying to take over from my drowsy self, and I'm well rested and have a great job!

[cinderball]

To be honest, I've always seen my car-sleepiness as an extension of my general sleepiness! Sitting still anywhere long enough will soon see me struggling to keep my eyes open.

[ahobimo]

My intuition was that the vibration was the key. Man, I love sleeping, when I'm a passenger in a a car.

[TheRogueWolf]

"Now I'm thinking that we need somebody to shake my bed!" - Hank Green, 2019

[AthAthanasius]

My immediate thoughts were some mix of: inadequate ventilation, sometimes hypnotic view as you drive and general lack of mental stimulation outside of that.

[Stammer]

My mom's truck literally has a "drivers' fatigue" monitor, which detects sway and speeds and lets you know when you should pull off to the side and stretch your legs. I was really intrigued by the feature

[Suutari]

Car is honestly the best place to sleep. It's so relaxing to hear the sound of the road, quiet music from the radio, feeling the turns while you're drifting off to sleep..

[zakiducky]

The white noise idea makes sense. Lots of people drive their babies around to get them to sleep. And when I still lived in the city, the noise of all the traffic was soothing and helped me sleep (except when sirens went off or someone honked like an idiot).

Also, my new car has _very_ stiff suspension and I feel every bump on the road. I get tired much, much more quickly than I did before.

[SanctuaryReintegrate]

I once slept for 45 minutes in the driver's seat on the interstate.
I never left the road, cruise control was still set when I woke up, and I had missed my exit by 3 miles.
It was one of the spookiest, most disorienting experiences of my life.
It's bizarre how people are able to steer a vehicle even after losing consciousness.

[Zappyguy]

I remember a small truck I used to drive, it's suspension was almost in sync with gaps in a concrete highway I regularly travel.
It would bounce in such a way that your head would nod as if you were falling a sleep and the action would encourage drowsiness while driving. I never nodded off but other drivers and myself noted that these vehicles were particularly sleep inducing.

[Im_a_piece_of_corn]

Thank you for putting this in focus for me. I've suffered from this for many years. I've always assumed it was a combination of AC, music, sitting down in a relaxed and quiet environment. Of course these are factors but I never considered the white noise of driving, vibration & losing focus. Well maybe focus but in other terms. I have a very creative & excitable mind - like that of a dreamer. I've always assumed since i wasn't doing anything 'artistic' my mind would just lose interest in whatever it is i'm doing. I can have all the energy in the world, feel well rested but hop in the car and after 5 minutes of driving or less, just completely doze off and it doesn't matter how good or happy a mood I am in. It's refreshing to see others suffer from this too. Glad i'm not the only one driving with one eye hardly open, the light of the world going out on me.

[fiercewarrior]

Who else gets tired after being in a car after 5 minutes 😂.

[matlavi]

I always fall asleep whenever I'm in the passenger seat. Some of my best naps happened on road trips.

[shotguun]

As a truck driver, I do notice it’s easier to sleep when the engine is idling vs when it’s not. Plus that nice A/C when it’s running is really nice.