Have you arrived home after a drive and not remembered the details of the drive? Almost everyone who drives has had this common experience, a phenomenon that has come to be called highway hypnosis.

Highway hypnosis naturally occurs when your attention is occupied with things other than your driving. It might be a song on the radio, a review of something significant that happened at work that day, or anything else that you get absorbed in while you’re driving your car. What’s fascinating is what highway hypnosis reveals about our mind’s ability to focus attention internally on our thoughts yet still maintain an external awareness of driving conditions in order to still drive safely (1). The fact that we can process and respond to information on multiple levels simultaneously represent one of the most sophisticated aspects of human consciousness and is the subject of fascinating neuroscientific research.

The recognition of highway hypnosis as a phenomenon was first written about in a 1921 article, where the author described it as 'road hypnotism.' The term 'highway hypnosis' wasn’t coined until much later by G. W. Williams in 1963 (2). At first, it was thought that highway hypnosis might be the cause of unaccountable motor vehicle crashes. However, researchers now understand that highway hypnosis isn’t the chief concern; rather, drowsy driving is the greater concern, especially so in these days when too many people are sleep deprived in general.

Driving Safely on Automatic

The old metaphor of consciousness being the visible tip of the iceberg and the unconscious being everything beneath the surface has been modified as more has been learned about non-conscious information processing. Many studies of mental processes have highlighted that people can absorb and respond to information without really being aware of it. Some neuroscientists have gone as far as suggesting that a more accurate metaphor is to describe consciousness as a snowball on top of the tip of the iceberg. The fact that people can be responsive to environmental cues, a phenomenon that scientists call priming, becomes especially relevant in the study of hypnosis. Priming gives rise to so-called “automatic” or non-conscious responses. This is what makes it possible to drive a car safely even when preoccupied with other things. This is quite a different process than what occurs when someone is simply too fatigued to drive safely, a point the statistics bear out. According to the National Highway Traffic Safety Administration, drowsy driving contributes to over 100,000 crashes and 6,500 deaths a year in the US (3). When driving drowsy, your reaction time is slowed and you become cognitively impaired, less aware of dangers and other cars.