Fatigue to blame for many big truck wrecks

Research (and common sense) have long established the serious problem of fatigue in causing or contributing to big truck wrecks.

Trucking accident cases

The problem of fatigue is systemic in 18-wheeler and commercial motor vehicle accidents, where profit motives lead many commercial motor carriers and their drivers to ignore the Federal Motor Carrier Safety Regulations (The Regs), which establish the maximum hours on duty rules for operators of commercial motor vehicles.

Put simply, The Regs provide that no motor carrier shall permit or require any driver, nor shall any driver, drive for more than 11 hours within a 14-hour window. A driver may not drive after the end of the 14-consecutive-hour period without first taking 10 consecutive hours off duty.

Additionally, no motor carrier shall permit or require any driver, nor shall any driver, drive a commercial motor vehicle after having been on duty more than –

  • 60 hours in any period of 7 consecutive days (if the motor carrier does not operate every day of the week), or
  • 70 hours in any period of 8 consecutive days (if the motor carrier operates every day of the week).

Further, no driver shall operate a commercial motor vehicle, and a motor carrier cannot require or permit any driver to operate the vehicle, while the driver’s alertness is impaired, or likely to become impaired, through fatigue, illness, or any other cause, as to make it unsafe for the driver to continue to operate the vehicle.

Determining whether fatigue played a role

Based on current scientific knowledge, any accident investigation must answer two questions:

Was the operator fatigued at the time of the accident?

To determine if an operator was fatigued at the time of the accident, an investigator evaluates an operator’s sleep loss or deprivation. Relevant factors include the operator’s sleep/wake history; continuous time awake before the accident; the operator’s Circadian rhythms; and the extent to which the sleep loss or deprivation was acute or chronic. In addition, the operator’s overall health must be considered to determine if an underlying medical condition, such as sleep apnea, contributed to a loss of sleep.

Did the operator’s fatigue contribute to the accident?

If the operator was fatigued, the investigator next determines whether the operator’s fatigue caused or contributed to the accident. If the operator’s actions contributed to the accident, the investigator will consider whether the operator’s performance was consistent with the known effects of fatigue as well as consider alternative explanations that could account for the operator’s performance.


  1. Price, J. & Coury, B. (2015). A Method for Applying Fatigue Science to Accident Investigation. Reviews of Human Factors and Ergonomics, Vol. 10, 2015, pp. 79-114.
  2. FMCSR §§ 392.3 and 395.3.

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