Have you ever had a moment behind the wheel when you've zoned out and suddenly snapped back into the present, realizing that you’ve not been concentrating on the road? You’re not alone. We assume that the subconscious brain takes over and is on guard to alert of any dangers. But this type of conscious brain switch off has a name - it’s called ‘highway hypnosis’. And far from being a simple case of our brain taking over the task at hand, it could actually lead to a serious risk of accident or injury – especially for professional drivers or people who spend a lot of time behind the wheel.
Driving can be monotonous, especially when covering long distances. It’s all too easy to turn on a playlist or an audiobook and slip into cruise control while the miles tick by almost unnoticed. But this kind of highway hypnosis is almost a trance-like state closely linked with sleepiness or drowsy driving, and this is when the risks of serious motor vehicle accidents increase. In fact, according to the National Highway Traffic Safety Administration, highway hypnosis contributes to over 100,000 crashes and 6,500 deaths each year in the U.S. alone.
What exactly is highway hypnosis, what causes it, and how can we avoid it when behind the wheel?
Highway hypnosis, also known as driving without attention mode (DWAM), is the mental state that drivers get into when covering long distances. It results in them being unaware of their surroundings and driving almost in an unconscious manner. Although this is a genuine and serious mental state, many drivers assume that it is a natural part of driving, with the subconscious brain taking over and staying alert. But this is not necessarily the case.
Highway hypnosis is often accompanied by tiredness or drowsiness, and while it’s not the same as daydreaming (as it's generally not accompanied by any kind of visions or illusions) it does result in a huge drop off in mental capacity and reaction times.
While there is not a single specific cause of the state of highway hypnosis, there are various contributing factors. One key factor is the monotony of the road, with a highly predictable environment with low event occurrences on motorways and familiar roads being a chief cause.
A 2003 study using a driving simulator saw 56 experienced drivers on two different simulated roads. Both roads were flat but one had only one type of visual element, pine trees spaced evenly on the road, and the other was designed with more varied visual stimulus. The results showed that drivers exhibited more signs of tiredness and fatigue on the more monotonous road. Even more surprising was the fact fatigue peaked after just 20 minutes of driving time, showing it doesn’t take long to succumb to highway hypnosis.
Another potential cause is not getting enough sleep. The likelihood of experiencing highway hypnosis is far higher when you are tired. Brain processes are slower, and you are far more likely to zone out and rely on autopilot instead.
However, even if you are not sleepy, brain inattention can cause highway hypnosis. That’s because after a long time on the road your brain will stop relying on retinal feedback from the oculomotor system and start to make more mental predictions about what might happen. In short, you become less alert.
There's no real difference between white line fever and drowsy driving or highway hypnosis. In essence, they are the same thing. However, the confusion arises because although driving without attention mode is a legitimate condition, it's not that widely known. White line fever is a name most generally used in the truck driving community for a loss of mental concentration on long drives or tedious journeys. However, this almost perfectly describes driving without attention mode or highway hypnosis.
The most obvious and significant danger of highway hypnosis is the risk of car accident. More than 100,000 motor vehicle accidents each year in the U.S. alone can be attributed to drowsy driving, with around 6,500 fatalities.
As well as the risks to yourself (a large percentage of highway hypnosis accidents involve single drivers coming off the road on rural roads or long highways) there is also a significant risk to other drivers and pedestrians.
Incidents of drowsy driving can also lead to increased car insurance premiums, vehicle and property damage, and loss of license. And with a truck driver shortage, there are risks that drivers will be asked to do more journeys and travel further. Even with the advent of self-driving trucks, the dangers of highway hypnosis remain a real and constant threat across the industry.
Part of the problem with highway hypnosis is that because it results in a dulling of your senses and awareness, it's not always easy to detect when it sets in. However, by being aware of the following symptoms you can spot the early signs and take steps to avoid highway hypnosis.
You should also be aware of exterior signs of highway hypnosis setting in, such as if your car hits the rumble strips on the edge of the road or drifts into other lanes.
There are several things you can do to prevent highway hypnosis and ensure safer driving on the roads. Including:
The longer you spend doing any one single thing, the greater the chances of the brain disengaging from what is happening. Take frequent breaks when behind the wheel, usually every hour or so, where you get out of the vehicle, walk around and re-engage your brain with your surroundings. This will help to prevent driver fatigue.
Open the window and get some fresh air in the vehicle, turn the heat down, listen to a different radio station or podcast – altering the external stimulus can help prevent the brain from switching off. You should also try and adjust your seating position so that you are more upright and have good posture.
Rather than traveling down the same, uninspiring road, try taking a new route with a range of different things to look at. This can help to prevent your brain from switching off.
Make sure that you get enough sleep before any long journey and eat lightly, as a heavy meal can make you more drowsy.
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