The Basics

A hazard is any potential source of harm, injury or adverse health effect to a person, or damage to something; an object, process or condition that may expose a person to risk of harm or injury.

Hazards, Causes and Contributing Factors

Using a traditional approach, the primary hazard or source of harm that we seek to eliminate is the motor vehicle incident (or “crash”). However, there are plenty of driving-related hazards that do not involve a crash. Improper seating positions that cause musculo-skeletal injuries, the mental toll of intensely challenging road conditions, or physical violence by a passenger are a few to consider.

As well, applying a traditional, and somewhat restrictive understanding of hazard does not work very well for road safety purposes. Conducting risk assessments using a vastly complex hazard such as “motor vehicle crash” would yield outputs that lack focus and not be sufficiently clear or actionable. A more constructive way to approach road safety risk assessments is to dig a little deeper and look at the practices, behaviours, objects, conditions and circumstances - the factors - that can cause or contribute to a crash.

Therefore, our consideration of driving-related hazards includes practices, conditions, objects and energies that traditional approaches might classify as contributing factors or risk factors.

Consider the following types of hazards and examples.

  1. Physical

    • objects - a sharp rock, wildlife, worn tire or faulty brake
    • substances – gasoline, brake fluid, carbon monoxide, drugs, alcohol
    • materials - gravel road surface, ice
    • temperature – extreme weather temperatures, contacting a hot surface
  2. Energy

    • kinetic – the vehicle you are in, or an oncoming vehicle
    • gravity - car falling off jack during tire change
    • electrical – shock from an incorrect jumper cable connection
    • noise - prolonged exposure to a loud exhaust system
    • pressure - compressed air or hydraulic fluid
  3. Conditions, processes and practices

    • conditions – fatigued driver, poor traction, insufficient lighting or visibility, stressful driving circumstances such as heavy traffic or aggressive drivers,
    • processes - insufficient driver training, lack of vehicle inspections or maintenance
    • practices – overloading vehicle; high-risk driving behaviours such as speeding, following too close or texting while driving; poor ergonomics such as improperly adjusted seat.

Risk is the possibility or potential for loss.

Three factors determine how much risk is associated with a given hazard:

  • Frequency of Exposure – how often and for how long workers are exposed to the hazard.
  • Probability of Occurrence – the likelihood that a MVI or other incident will occur.
  • Severity of Consequences – the magnitude of loss, negative consequences or impacts.

The following formula explains risk.

Risk = Exposure x Probability x Severity

In the risk equation, implementing measures that make any one of the variables zero also makes the risk zero. For example, if no worker is exposed to a hazard, exposure equals zero and risk is zero.

Download Hazard ID and Risk Assessment Basics (PDF 297KB)

Find other helpful terms and definitions in our Glossary.


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The Basics

Hazard Identification

Risk Assessment

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