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CMV Driving Tips - Driver Fatigue

Fatigue is the result of physical or mental exertion that impairs performance.46 Driver fatigue may be due to a lack of adequate sleep, extended work hours, strenuous work or non-work activities, or a combination of other factors.14 The Large Truck Crash Causation Study (LTCCS) reported that 13 percent of commercial motor vehicle (CMV) drivers were considered to have been fatigued at the time of their crash.15

Below are some tips that will help you stay healthy and well rested during all your trips.

TIP #1: Get Enough Sleep Before Getting Behind the Wheel

Be sure to get an adequate amount of sleep each night. If possible, do not drive while your body is naturally drowsy, between the hours of 12 a.m. to 6 a.m. and 2 p.m. to 4 p.m. Driver drowsiness may impair a driver’s response time to potential hazards, increasing the chances of being in a crash.16 If you do become drowsy while driving, be sure to choose a safe place to pull over and rest.

Did You Know? The circadian rhythm refers to the wake/sleep cycle that our body goes through each day and night. The cycle involves our internal clock and controls the daily pattern of alertness in a human body. With inadequate sleep, the drowsiness experienced during natural "lulls" can be even stronger and may have a greater adverse effect on a driver’s performance and alertness.47

Did You Know? A study by the Federal Motor Carrier Safety Administration (FMCSA) found that driver alertness was related to "time-of-day" more so than "time-on-task."48 Most people are less alert at night, especially after midnight. This drowsiness may be enhanced if you have been on the road for an extended period of time.16

Did You Know? A recent study conducted to determine the risk of having a safety-critical event as a function of driving-hour suggests that incidents are highest during the first hour of driving. The authors hypothesize that drivers may be affected by sleep inertia shortly after waking from sleep. This may be especially true for drivers who sleep in the sleeper berth.49 Sleep inertia refers to impairment in a variety of performance tasks, including short-term memory, vigilance, cognitive functioning, reaction time, and ability to resist sleep.49,50,51,52

An example of a fatigued driver is shown in the video below. Training exercise questions follow the video clip.

VIDEO DESCRIPTION: The CMV driver is traveling in the right lane of a two-lane road at night. The driver is clearly drowsy, making it difficult for him to pay attention to the roadway. The driver drifts towards the right shoulder of the road, nearly hitting the curb, before he returns the truck to the lane.

TRAINING EXERCISE: After viewing the video, try to answer the following questions:

  • What behaviors indicate that the driver is drowsy?
  • What happened as a result of the driver’s drowsiness?
  • How did the driver correct his mistake?
  • What could the driver have done differently?

TIP #2: Maintain a Healthy Diet

Skipping meals or eating at irregular times may lead to fatigue and/or food cravings. Also, going to bed with an empty stomach or immediately after a heavy meal can interfere with sleep.53 A light snack before bed may help you achieve more restful sleep. Remember that if you are not well-rested, induced fatigue may cause slow reaction time, reduced attention, memory lapses, lack of awareness, mood changes, and reduced judgment ability.

Did you Know? A recent study conducted on the sleeping and driving habits of CMV drivers concluded that an unhealthy lifestyle, long working hours, and sleeping problems were the main causes of drivers falling asleep while driving.54

TIP #3: Take a Nap

If possible, you should take a nap when feeling drowsy or less alert. Naps should last a minimum of 10 minutes, but ideally a nap should last up to 45 minutes. Allow at least 15 minutes after waking to fully recover before starting to drive.55

Did you know? Short naps are more effective at restoring energy levels than coffee.16

Did you know? Naps aimed at preventing drowsiness are generally more effective in maintaining a driver's performance than naps taken when a person is already drowsy.47

TIP #4: Avoid Medication That May Induce Drowsiness

Avoid medications that may make you drowsy if you plan to get behind the wheel. Most drowsiness-inducing medications include a warning label indicating that you should not operate vehicles or machinery during use.16 Some of the most common medicines that may make you drowsy are: tranquilizers, sleeping pills, allergy medicines and cold medicines.56

Did You Know? In a recent study, 17 percent of CMV drivers were reported as having “over-the-counter drug use” at the time of a crash.15

Did You Know? Cold pills are one of the most common medicines that may make you drowsy. If you must drive with a cold, it is safer to suffer from the cold than drive under the effects of the medicine.16

TIP #5: Recognize the Signals and Dangers of Drowsiness

Pay attention: Indicators of drowsiness include: frequent yawning, heavy eyes, and blurred vision.57

Did You Know? Research has indicated that being awake for 18 hours is comparable to having a blood alcohol concentration (BAC) of 0.08 percent, which is legally intoxicated and leaves you at equal risk for a crash.57

Did You Know? A 2005 study suggests that three out of every four CMV drivers report having experienced at least one type of driving error as a result of drowsiness.58

Did You Know? On October 16, 2005 at 2 a.m., a 23-year-old CMV driver fell asleep behind the wheel, causing him to enter a ditch and eventually roll his truck over on both west-bound lanes of Interstate 94. Minutes later, a charter bus carrying a school band crashed into the truck killing 5 and injuring 29 others. As a result of the crash, the CMV driver was charged with 5 counts of homicide by negligent operation of a vehicle and 29 counts of reckless driving that caused great bodily harm. If convicted he could have faced nearly 90 years in prison.59,60,61

TIP #6: Do Not Rely on "Alertness Tricks" to Keep You Awake

Behaviors such as smoking, turning up the radio, drinking coffee, opening the window, and other “alertness tricks” are not real cures for drowsiness and may give you a false sense of security.

Did You Know? Excessive intake of caffeine can cause insomnia, headaches, irritability, and nervousness.53

Did You Know? It takes several minutes for caffeine to get into your system and deliver the energy boost you need, so if you are already tired when you first drink a caffeinated drink, it may not take effect as quickly as you might expect. In addition, if you are a regular caffeine user, the effect may be much smaller.62

Did You Know? Rolling the window down or turning the radio up may help you feel more alert for an instant, but these are not effective ways to maintain an acceptable level of alertness.63