Alcohol and drugs are often assumed to be behind impaired driving. Yet, sleep deprivation, which can affect as many as 44 percent of adults on any given day, can produce similar driving impairments and the same deadly consequences. The reason—sleep deprivation changes the way the brain functions.
One of the first changes is in the time the glymphatic system has to cleanse the interstitial spaces in the brain. The glymphatic system is 90 percent more active at night than during the daytime. This system flushes out the spaces between brain cells where toxic proteins and amino acids collect throughout the day. Without that important cleansing time, the interstitial spaces clog, reducing the efficiency with which the brain can send and receive messages.
Additionally, lack of sleep causes neurons to slow the rate at which they fire. Slowed messages lead to cognitive lapses that affect thinking and response times. Sleep deprivation also causes the brain to increase levels of adenosine to further slow the brain. Adenosine acts as the brain’s last-ditch effort to slow the body into a sleep state. For drivers, a two-second delay in processing time can mean the difference between safely navigating the road and an accident.
The sleep-deprived brain’s ability to process information and respond to it rival those of one that is legally intoxicated. In a comparison of drivers with a blood-alcohol level of .08 percent and drivers who’d been awake for 21 hours, it was found that drivers showed similar symptoms of driving impairment. Irregular speed changes and drifting out of driving lanes marked both sets of drivers.
Drowsy driving can, at times, be more dangerous in that drivers do not realize that their driving abilities are compromised. They may notice the heavy, drooping eyelids and excessive yawning, but it’s the cognitive differences such as memory lapses, slowed reaction times, and inability to assess situations that put the driver, their passengers, and other drivers at risk.
Anyone can find themselves at risk for drowsy driving. However, some populations and occupations are at higher risk than others. Seniors and teenagers, for example, show higher instances of altered sleep patterns due to changing biological factors. With age, the quality of the sleep cycle degrades as do many systems like the glymphatic system, that are responsible for keeping the brain working at peak efficiency.
Adolescents, on the other hand, often experience sleep phase delay wherein their sleep cycle starts one to two hours later than normal. Coupled with early school start times, many teens are chronically sleep-deprived whether at home, school, or on the road.
Occupational hazards have become more common as well. In a global economy, shift work has increased, putting more drivers on the road late at night and in the early morning when most drowsy driving accidents occur. While trucks drivers, medical professionals, and business travelers used to be the main culprits for occupational drowsy driving, the numbers have extended to a number of industries that compete for customers 24/7.
While all drowsy driving may not preventable, a good portion is. Bedrooms created to support sleep through dark, cool, quiet conditions along with a supportive mattress that helps eliminate aches and pains are good places to start improving sleep quality.
However, in a world where lightbulbs and laptops can stay lit and running all night, a commitment to a full seven to nine hours of sleep is needed for long-term success. Regular bedtimes, bedtime routines, disciplined use of technology, and time spent outside are all ways to improve sleep quality and lengthen sleep time.
When the brain is given the time it needs to maintain itself, cognitive abilities remain intact. Accidents happen, but with a full night’s rest, drowsy driving accidents won’t.