Impaired driving is operating any type of land, air or water vehicle while under the influence of:

  • alcohol
  • cannabis and other mind-altering drugs
  • fatigue
  • prescribed and over-the-counter medications
  • Blood alcohol concentration (BAC)

    Blood alcohol concentration (BAC)

    BAC is the amount of alcohol in your blood. Along with how much alcohol you drink, other factors affect your BAC, such as your sex, weight, medications, mood, how fast you drink, and tiredness.

    Typical affects from drinking to much include:

    • blurred vision
    • loss of balance
    • poor reaction time

    The higher your BAC the worse your motor skills, reaction time, and vision become. No amount of alcohol is safe when driving, but with a BAC over 0.05% fatalities and serious penalties can occur.

    Help and statistics

  • Cannabis and driving

    Affects of driving high

    Marijuana use can be less visible than that of alcohol, but you are impaired just the same. Some of these effects include:

    • reduced ability to divide your attention
    • poor time and space management
    • loss of concentration

    Driving high may also impair motor functions, such as:

    • coordination
    • balance
    • judgement
    • reaction time

    Consuming alcohol and cannabis

    Combining alcohol and cannabis impairs a driver more than consuming cannabis or alcohol on their own. When combined, even at low levels, a greater level of intoxication occurs and your ability to drive decreases and the risk of collision increases.

  • Fatigue and driving

    Driving while tired is impaired driving. Being awake for 17 to 19 hours is equivalent to having a blood alcohol content of 0.05%.

    Symptoms of fatigue can result in a driver:

    • being unable to react to something on the road
    • taking greater risks while driving
    • reacting more emotionally or aggressively to situations
    • blinking or closing their eyes for longer periods of time
    • falling asleep at the wheel

    Falling asleep at the wheel is a serious concern on our roads. 20% of fatal collisions in Canada involve driver fatigue. In Alberta in 2017, over 200 drivers involved in a serious injury or fatal collision were reported as fatigued or asleep.

  • Medication and driving

    Medication, whether prescribed or over the counter, can impair your ability to operate a vehicle safely.

    Effects that prescription drugs can have on drivers include:

    • slowed reaction time
    • sleepiness
    • poor psychomotor performance
    • impaired coordination
    • reduced ability to divide attention
    • increased errors
    • difficulty following instructions

    Driving with a medical condition may make you more vulnerable to the side effects of prescription drugs because you may combine multiple medications.

    The following prescription and over-the-counter drugs have the potential to impair driving:

    • cannabis
    • tranquilizers
    • narcotic pain pills
    • sleep medicines
    • some antidepressants
    • cough medicines
    • antihistamines
    • decongestants 

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