why do I feel sleepy on the bus?
Questions And Answers

Why Do I Fall Asleep on The Bus?

(Last Updated On: June 22, 2022)

Have you ever dozed off on the bus or train while commuting to work?

If so, there’s no need to worry – you’re not alone. Many people fall asleep on the bus or trains, even if they’re not necessarily tired, especially on a long journey.

This isn’t limited to public transport, either. For example, many children fall asleep in cars, even if they feel sick or have trouble sleeping.

Factors that could be at work include:

  • Fatigue and tiredness
  • The presence of white noise
  • Comfort
  • Temperature
  • Sopite syndrome

With that said, some people are less prone to this than others, just as some people are more likely to feel nauseous in a moving vehicle. There are both psychological and physical components to this common phenomenon. So, everyone experiences it a little differently.

For example, some people may feel tired but be unable to sleep. Meanwhile, others will fall into a deep sleep without much trouble.

Falling asleep in a moving vehicle can have many different implications for your body and, of course, your day, especially if you fall asleep on a bus or other public transport.

Why Do I Feel Sleepy On the Bus?

There are fundamental reasons for feeling sleepy on the bus, train, or other forms of transport. These can be split into two main categories:

  • Sopite syndrome
  • Sleep deprivation

Sleep Deprivation

If you find that you don’t always fall asleep on buses and trains, but you start to doze very quickly when you do, the most likely cause is sleep deprivation.

The likelihood of falling asleep on public transport as a result of sleep deprivation is affected by several factors, including:


Many studies show the importance of temperature when it comes to sleep and sleep quality.

According to Frontiers in Neuroscience, in a study on gating and maintenance of sleep schedules, warmth is often a gate or trigger for sleep.

This is due to how mammalian bodies cool at certain points in the body’s circadian cycle. Furthermore, being very warm can cause drowsiness and lethargy because the body uses energy to cool itself. 


Comfort plays a huge role in our ability to sleep well. However, when we’re sleep deprived or very tired, we may find it easier to sleep in less comfortable positions, such as sitting upright.

If you’re lucky enough to get a good, comfortable seat on the bus or train when you’re already exhausted, the likelihood of falling asleep will increase.

Journey Length

Boredom and protracted periods of inactivity can induce drowsiness and sleep in many people. The lower level of stimuli can make it easy to descend into sleep.

There is also a phenomenon known as highway hypnosis. This can occur during long journeys in a relatively bland landscape (for example, on a highway), where the lack of stimulation causes a trance-like state.

So, these factors combine with sleep deprivation to induce sleep in almost anyone on a bus.

What if you habitually fall asleep on the bus, train, or subway, regardless of how much sleep you had the night before? Then, you may have a neurological condition called sopite syndrome.

What is Sopite Syndrome?

Sopite syndrome is a less-understood neurological disorder, which is connected to motion sickness, as well as sleepiness during transport.

According to Acta Astronautica, sopite syndrome can include symptoms such as:

  • Nausea
  • Mood swings
  • Drowsiness

The study also notes that sopite syndrome is distinct from motion sickness, despite sharing some symptoms. It can also be triggered by simulating transport conditions.

Additionally, Human Factors suggest a link between sopite syndrome and lower multitasking abilities.

For most people, sopite syndrome isn’t a serious issue, but in some people, the symptoms are severe. For example, while many people may feel the effects of sopite syndrome as passengers, few will experience them as drivers.

Of course, long journeys and extreme fatigue can increase the severity of sopite syndrome symptoms and make it significantly more serious. Nonetheless, this isn’t likely to cause long-term health problems.

The most serious outcomes for those with sopite syndrome (notably, injury or fatality) occur not because of the syndrome. Instead, it’s because of accidents that occur due to its symptoms.

For example, someone experiencing a severe form of sopite syndrome might be at risk of falling asleep behind the wheel on long journeys. This can, of course, be extremely dangerous.

nodding off on the bus

What Happens if You Fall Asleep on the Bus?

So, what happens to your body if you fall asleep in a moving car, bus, or train? The answer is pretty much the same as when you sleep in a bed or on a sofa.

Your awareness of the world around you drops, and you will enter a sleep cycle. The National Institute of Neurological Disorders and Stroke indicates that, during sleep, your:

  • Body temperature will lower, partly as a result of inactivity
  • Breathing will slow, along with your heart rate
  • Muscles will relax
  • Certain hormone levels in your body will also change

However, sleeping on a bus or train will make it hard for you to get a satisfying sleep. Bumps on the road, noise, and the uncomfortable nature of sleeping upright are likely to lead to:

  • Broken sleep
  • Increased stress levels
  • Grogginess
  • Disorientation
  • Increased feelings of nausea

This can be unpleasant and make you feel worse in the long term. While stressful, falling asleep on the bus isn’t necessarily dangerous in and of itself.

Is Falling Asleep on Public Transport Safe?

Sleeping on public transport can be dangerous from time to time. However, this is rarely to do with the nature of sopite syndrome or any other underlying cause of sleep.

Most of the dangers associated with sleeping on public transport come from outside. That is to say, from environmental factors or, of course, the other people on public transport.

One danger associated with sleeping on public transport that doesn’t involve other passengers is the danger of falling.

Depending on where you’re sitting, you may find that the normal turbulence caused by navigation leads to you falling out of your seat. Of course, this is more likely on a bus than a train because of the tight corners and chance of potholes in the roads.

The other dangers associated with sleeping on a public bus or train are:

  • Theft
  • Assault
  • Molestation
  • Legal issues

When potential victims are asleep, intoxicated, or otherwise in a reduced state of alertness, there is an increased risk of:

  • Pickpocketing
  • Robbery (armed or otherwise)
  • Molestation
  • Sexual harassment
  • Assault (physical or sexual)

The risk level isn’t the same everywhere, as some places are more dangerous than others. Nonetheless, falling asleep will increase any risk level further.

How to Not Fall Asleep on the Bus

Have you developed a habit of falling asleep on the bus or train on the way to work? Do you want to stop doing it? Then there are steps you can take:


The easiest approach is to stand rather than sit. However, this isn’t always viable, as some bus providers don’t allow passengers to stand. Likewise, other buses or trains may lack the space.

Bring Your Temperature Down, and Sit Uncomfortably

If you can’t stand to prevent dozing or sleeping on long journeys, your approach to staying awake should be twofold. The physical component concerns factors like your:

  • Body positioning
  • Temperature

Try to sit upright rather than leaning. Likewise, open a window or remove your sweater or jacket to lower your temperature. If you do this, you’ll considerably lower the chance of falling asleep. This may not be sufficient on long journeys, though.

Stay Busy

The psychological element of preventing drowsiness involves preventing boredom and keeping your mind moving. Boredom is the most common factor in drowsiness when traveling.

So, keep yourself occupied and stimulate your brain. If you want to stay alert, you can try:

  • Reading
  • Puzzles
  • Listening to music
  • Knitting/crochet
  • Writing

These activities can help you stay awake by stimulating your mind, using problem-solving skills, or giving you something to focus on. They are also quite easy to do on public transport, as they:

  • Don’t take up a large amount of space
  • It can be undertaken in short bursts
  • Won’t be disruptive to the people around you

Whatever you do, choose something you find enjoyable. This ensures that it’s easy to maintain focus. With these tips, you should find staying awake on the bus or train easier.