Fatigued Driving

Master the art of staying awake and alert

Professional drivers face countless daily challenges that lead to fatigue.
It’s important to remember that fatigue doesn’t just happen at night; it can happen any time of day, and it affects your drivers’ ability to safely operate a vehicle. Fatigued or drowsy driving
is one of the most common causes of vehicle accidents. The good news is, it’s preventable!
“Fatigue” is a generic term for anything from tiredness to exhaustion. The term fatigue can apply to both the physical body and to the spirit, and extreme fatigue can cause an uncontrolled shutdown of the brain. The first step in preventing fatigue is knowing the signs.

Signs and signals

The most obvious signs of fatigue are usually physical: yawning, heavy eyelids, clumsy movements, frequent blinking, and/or nodding off. Most people are already familiar with these signs, but there are some other less obvious signs that your drivers should know, too.
These can include mental and emotional effects of fatigue, like:
• Slowed reaction time,
• Poor decision-making, and
• Memory issues.
Other signs of fatigue may appear as driving errors, like:
• Missing an exit,
• Driving on the rumble strip,
• Drifting between lanes,
• Erratic speed control,
• Inconsistent shifting,
• Intermittent braking, and
• Following other vehicles too closely.

What causes fatigue?

There are two major causes of fatigue for professional drivers: sleep loss and changes to circadian rhythms.

Sleep loss

Most adults need between 6-8 hours of uninterrupted sleep per night to feel rested. The human body can sometimes function on less sleep, but after a few days, a sleep debt develops. For example, if you need 8 hours of sleep but only get 6, then you have a 2-hour sleep debt. If you lose those 2 hours for four days in a row, then you have an 8-hour sleep debt — that’s a whole
night’s worth!
Even just 2 hours of sleep loss can cause reduced judgment, slowed reaction time, a lack of concentration, and poor mood/attitude.

Circadian rhythms

Most people have an internal clock that runs on a 24-hour basis with high and low points, which is called a circadian rhythm. Time cues like sunlight and personal work/rest times keep the body’s internal clock set to a certain schedule. The morning low point between 2:00 a.m. and 6:00 a.m. is the most dangerous. Most people are programmed to sleep at this time since it’s dark out,
which makes it difficult to fight fatigue.
If the internal clock is changed to a different schedule, like when changing time zones or working a new shift, the body needs time to adjust to the new schedule. These time transitions can disrupt the body’s internal clock and cause fatigue and sleep loss.

How to fight fatigue

The best way to fight fatigue is to maintain a regular sleep schedule. This means going to sleep at the same time every night and sleeping for 6-8 interrupted hours.
Drivers can also help prevent their own fatigue by:
• Developing a bedtime routine that limits food and screen time for 30-60 minutes before bed;
• Avoiding driving during the body’s low points;
• Eating nutritious, high-energy food at regular intervals to help regulate energy levels; and
• Taking breaks to reduce the time-on-task and risks of distractions.