Driver Fatigue: Causes, Symptoms, and Prevention Measures

Discover the profound effects of driver fatigue on health, the public, and your fleet. Learn actionable strategies to prevent and manage it effectively.

What is Driver Fatigue?

Driver fatigue, often referred to as drowsy driving, is a state of physical and mental exhaustion that significantly diminishes a driver’s capacity to operate a vehicle safely. This condition impairs crucial driving functions such as alertness, concentration, and the ability to respond to hazards on the road. Understanding driver fatigue involves recognizing its causes, symptoms, and the substantial risks it poses to road safety.


Driver fatigue has far-reaching implications that affect not only the driver but also the public, fleet safety, and the broader economic landscape. Here are the key impacts of driver fatigue:

High Risk of Accidents

Fatigued drivers experience impaired reaction times and reduced focus, greatly increasing the likelihood of accidents. One of the most severe consequences of driver fatigue is its significant potential to cause road accidents. Globally, between 10% and 20% of all road crashes are attributed to fatigue, according to estimates. In the UK alone, it was estimated that in 2022, there were approximately 1,300 collisions resulting in injuries.


Accidents involving fatigued drivers are around 50% more likely to lead to death or severe injury than other accidents. According to the US Transportation Secretary, nearly 4,000 fatalities occur annually in large truck crashes, with driver fatigue as a primary factor. This elevated risk is due to high-speed impacts, as fatigued drivers often fail to brake or swerve to reduce the impact.

Chronic Health Issues

The demanding work environment and lifestyle factors experienced by many drivers, including chronic fatigue, can significantly increase their risk of developing a range of serious long-term health problems if not properly addressed. These health issues for drivers include the following:

  • Obstructive Sleep Apnea (OSA)
  • Cardiovascular diseases
  • Adult-onset diabetes
  • Obesity
  • Hypertension

Public Safety Concerns

Another major concern surrounding driver fatigue is its negative impact on public safety. Fatigued drivers endanger not only themselves but also other motorists, pedestrians, and cyclists. The inability to maintain control of the vehicle or respond promptly to hazards increases the risk for everyone on the road.

Economic and Operational Implications

The annual cost of crashes caused by drowsy drivers, resulting in injury or death, is estimated by the US National Highway Traffic Safety Administration to be more than $109 billion. For fleet operators, driver fatigue can lead to increased insurance premiums, vehicle damages, and lost productivity. These economic consequences underscore the need to understand driver fatigue and implement effective preventive measures.

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Several factors can contribute to driver fatigue, such as long work hours, inadequate rest breaks, and poor sleep quality. Other common causes include:

  • Sleep disorders
  • Intense or demanding work schedules
  • Medications or drugs that cause drowsiness
  • Alcohol consumption
  • Long highway drives
  • Driving during the body’s natural rest periods (e.g., early morning hours)
  • High stress levels and irregular work shifts


Fatigue is a gradual process that accumulates over time and can lead to various symptoms, including:

Physical Symptoms

  • Excessive yawning or heavy eyelids
  • Blurred vision or difficulty keeping eyes open
  • Muscle weakness and body aches
  • Headaches and dizziness

Behavioral Symptoms

  • Difficulty maintaining focus or drifting between lanes
  • Frequent blinking or rubbing of the eyes
  • Daydreaming or zoning out while driving
  • Nodding off at the wheel or missing road signs

Cognitive Symptoms

  • Slower reaction time to hazards on the road
  • Poor decision-making skills
  • Memory lapses and difficulty concentrating

Regulations and Guidelines

To address driver fatigue, many countries have implemented regulations and guidelines for commercial drivers.

US – Federal Motor Carrier Safety Administration (FMCSA) Regulations

In the US, the FMCSA, a branch of the U.S. Department of Transportation, oversees the trucking industry. Their objective is to enhance safety and reduce the incidence of crashes, injuries, and fatalities involving large trucks and buses. Key details on the regulations include:

Hours of Service (HOS)

The US FMCSA requires drivers to adhere to specific limits on driving HOS and mandatory rest breaks. These regulations apply to all Commercial Motor Vehicles (CMVs) involved in interstate commerce. A key guideline here is the maximum driving hours: drivers can operate their vehicles for up to 11 hours, after which they must take a mandatory 10 consecutive hours off-duty.

Chain of Responsibility (CoR)

The CoR laws allow the US FMCSA to enforce actions against everyone in the supply chain, not just the driver. With this, shippers, brokers, carriers, and logistics providers can be held responsible for allowing fatigued or unsafe driving.

Australia – National Heavy Vehicle Regulator Guidelines (NHVR) 

The NHVR in Australia manages the Heavy Vehicle National Law (HVNL) and supervises five regulatory frameworks for heavy vehicles with a gross vehicle mass of over 4.5 tonnes. NHVR’s main regulations include:

Heavy Vehicle (Fatigue Management) National Regulation

The HVNR covers the fatigue management requirements for heavy vehicle drivers. It includes work and rest hour limits, mandatory rest breaks, fatigue management accreditation schemes, responsibilities of parties in the supply chain, and record-keeping.

Electronic Work Diaries (EWD)

The NHVR strongly advocates for the adoption of EWDs to ensure precise recording of drivers’ work and rest hours. EWDs offer streamlined reporting and bolster compliance with fatigue management regulations.

UK – Driver and Vehicle Standards Agency (DVSA) Regulations

In the UK, the DVSA oversees the safety regulations for drivers and vehicles. DVSA can check vehicles, drivers, and operators to ensure compliance with road safety laws, including driver fatigue regulations, such as:

EU Drivers’ Hours Rules

  • Drive no more than nine  hours a day (maximum 56 hours a week)
  • Take a 45-minute break after every 4.5 hours of driving
  • Rest for 11 hours daily (can be reduced to nine hours up to there times a week)
  • Rest for 45 hours weekly (can be reduced to 24 hours every two weeks)

Working Time Regulations

  • Limit average weekly work to 48 hours (over the span of 17 weeks)
  • Require 11 consecutive hours of daily rest
  • Provide a 30-minute break for work over six hours
  • Mandate a 24-hour weekly rest period

Fatigue Management National Regulation

  • Mandate that fleet operators implement a fatigue risk management system
  • Mandate that operators must not allow fatigued drivers to drive

Prevention Measures for Driver Fatigue

Given the laws and regulations to address driver fatigue, individuals and organizations need to take necessary steps to prevent it. Some effective measures include:

Driver Fatigue Management Systems

These are systems that monitor drivers’ fatigue through various means, including tracking eye movement and steering wheel vibrations. These systems can alert sleepy or fatigued drivers to take a break before reaching dangerous levels of exhaustion.

Driver Fatigue Management Courses

Courses on driver fatigue management teach commercial drivers how to prevent and combat fatigue while driving. They cover various topics, including identifying signs of fatigue, ways to boost alertness, and managing sleep schedules.

Balanced Work Schedules

Balanced work schedules mean allowing drivers adequate rest and not pressuring them to meet unrealistic deadlines. Employers should also consider the time of day when scheduling trips, avoiding peak fatigue hours.

Fleet Management Policies

Establishing policies and procedures for managing driver fatigue can significantly reduce the risk of fatigued driving. These are guidelines that ensure the efficient, safe, and cost-effective operation of vehicle fleets. They include maintenance schedules, safety standards, driver training, compliance with regulations, and the use of telematics for monitoring and improvement.

Technology and Data Analytics

Another preventative measure for driver fatigue is using technology and data analytics. These include monitoring systems, fatigue detection, telematics, sensors, and other tools to track driver behavior and alert them or their employers of potential issues. Fleet managers can collect real-time data on driver behavior, route planning, and vehicle health through these systems.

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Guidelines for Fleet Managers

Aside from understanding regulations and preventative strategies, fleet managers should also do the following to prevent driver fatigue:

  1. Implement Fatigue Management Policies: Establish comprehensive policies and procedures on driver fatigue management, including regular breaks, shift rotation, and maximum driving hours.
  2. Prioritize Driver Education and Training: Train drivers on the risks and effects of fatigue, how to recognize it, and how to manage it.
  3. Invest in Fatigue Monitoring Systems: Investing in technology is never a financial burden. Adapting to fast-advancing technology is vital for fleet safety.
  4. Foster a Supportive and Safety-Oriented Culture: Create a culture that prioritizes safety and encourages open communication between drivers and management.
Loida Bauto
Article by

Loida Bauto

SafetyCulture Content Contributor
Loida Bauto is a freelance content contributor for SafetyCulture and a self-published book author. She has written various articles about workplace safety, human disabilities, universal design, and sustainability. Her written works reflect her strong passion for quality, workplace incident prevention, and efficiency to empower businesses to improve their operations.