Why Underestimating Drowsiness Leads to Crashes

Drowsy driving is a widely experienced yet often underestimated issue among drivers, leading to a significant role in traffic crashes, injuries, and fatalities.

While government statistics may not fully capture its extent, the AAA Foundation for Traffic Safety research suggests that around 16% to 21% of fatal vehicle crashes involve drowsy driving.

A recent study by the Foundation revealed that drivers tend to underestimate their drowsiness, leading them to continue driving instead of taking a necessary break.

Educating on the Early Signs

Dr. David Yang, the president and executive director of the Foundation, warns that driving while drowsy is a dangerous form of impairment that doesn't improve with continued driving.

The objective is to educate drivers about early warning signs of drowsiness so they can recognize when it's time to stop, rest, and continue their journey safely.

Drowsiness refers to an increased tendency to fall asleep, which poses the risk of dozing off at the wheel and impairs a driver's alertness.

Crashes caused by drowsy driving can be severe as the driver may not attempt to avoid the collision, resulting in high-speed impacts. Additionally, a drowsy driver may lose control of the vehicle due to being startled.

Drivers Underestimated Their Level of Drowsiness

To better understand the impact of drowsiness, researchers conducted a simulated nighttime highway driving experiment covering 150 miles.

Participants could stop at simulated "rest areas" every 20 miles to rest, nap, or refresh themselves. The study found that drivers' perception of their drowsiness didn't always align with their actual level of sleepiness, affecting their decision-making on when to take breaks.

Key findings from the study include:

• Drivers often underestimated their level of drowsiness, with 75% rating themselves as less drowsy than they actually were.
• Even when drivers' eyes were closed for extended periods, indicating severe drowsiness, one in four still rated their drowsiness as low.
• Drivers rarely took breaks unless they felt extremely drowsy, and even then, they declined 75% of their opportunities to rest and kept driving.

The results highlight the need for drivers to recognize their level of drowsiness and be aware of warning signs to avoid falling asleep while driving.

Look out for These Common Symptoms  

Common symptoms of drowsiness include difficulty keeping eyes open, lane drifting, and difficulty recalling the last few miles driven.

Drivers should not wait for their bodies to give them an alarm; it's crucial to prioritize getting at least seven hours of sleep before embarking on a journey. AAA recommends several measures to prevent drowsy driving:

• Travel during times when you are normally awake.
• Avoid heavy meals before driving.
• Refrain from using medications that cause drowsiness or impairment.

For longer trips, drivers are advised to take breaks every two hours or every 100 miles, consider traveling with an alert passenger to share driving duties, and not underestimate the benefits of a short nap (around 20 to 30 minutes) at rest stops to stay alert.

AAA supports the development of vehicle technology that can passively monitor drivers for impairment and intervene if necessary, including detecting drowsiness, medical impairment, or the influence of drugs or alcohol.

The 2021 Infrastructure Investment and Jobs Act mandates NHTSA to establish testing standards for such technology to enhance road safety.