How Alcohol and Cannabis Impact Driving: Understanding Impairment and Liability in Ontario

June 17, 2026, Kitchener, Ontario

Posted by: Robert Deutschmann, Personal Injury Lawyer

Most Canadians understand that impaired driving is dangerous. Yet every year, alcohol and cannabis continue to contribute to serious collisions, catastrophic injuries, and preventable deaths on Ontario roads.

While public awareness has improved significantly over the past several decades, misconceptions remain regarding how substances affect a driver's ability to operate a vehicle safely.

Whether impairment results from alcohol, cannabis, or a combination of both, the risks are substantial.

How Alcohol Affects Driving Ability

Alcohol impacts nearly every function required for safe driving.

Even small amounts can affect:

• Judgment
• Coordination
• Reaction time
• Vision
• Concentration
• Decision-making

Drivers who consume alcohol often become overconfident while simultaneously experiencing reduced ability to recognize hazards and respond appropriately.

This dangerous combination contributes to countless preventable collisions every year.

How Cannabis Affects Driving Ability

Since cannabis legalization, concerns regarding drug-impaired driving have increased.

Cannabis can affect:

• Depth perception
• Attention
• Motor coordination
• Reaction time
• Decision-making
• Ability to track moving objects

Many users mistakenly believe cannabis makes them safer or more cautious drivers.

Research consistently shows that impairment can significantly reduce a driver's ability to respond effectively to changing road conditions.

Combining Alcohol and Cannabis

One of the most dangerous situations occurs when alcohol and cannabis are used together.

The impairing effects can compound one another, resulting in substantially greater impairment than either substance alone.

Drivers may experience:

• Slower reaction times
• Poor judgment
• Reduced coordination
• Increased risk-taking behaviour

These factors dramatically increase collision risks.

The Human Cost of Impaired Driving

Behind every impaired driving collision are real people whose lives can be permanently altered.

Victims may suffer:

• Traumatic brain injuries
• Spinal cord injuries
• Chronic pain
• Psychological trauma
• Permanent disability
• Loss of income

Families often face years of recovery and emotional hardship.

Ontario's Impaired Driving Laws

Ontario maintains strict laws regarding impaired driving.

Drivers suspected of impairment may face:

• Criminal charges
• Licence suspensions
• Vehicle impoundment
• Significant fines
• Increased insurance premiums
• Potential imprisonment

The legal consequences can be severe, but they pale in comparison to the consequences of causing serious injury or death.

Preventing Impaired Driving

Safe alternatives include:

• Designated drivers
• Ride-sharing services
• Public transit
• Taxis
• Staying overnight when necessary

Planning ahead remains one of the most effective ways to prevent tragedy.

Accountability Matters

When an impaired driver causes a collision, injured victims have rights.

Personal injury claims may help victims recover compensation for:

• Medical expenses
• Rehabilitation costs
• Income loss
• Future care needs
• Pain and suffering

Holding negligent drivers accountable helps promote safer roads for everyone.

Make the Safe Choice

Whether the impairment stems from alcohol, cannabis, or both, the safest decision is always the same: do not drive.

If you or someone you love has been injured by an impaired driver, Deutschmann de Koning Personal Injury and Disability Law is here to help. Our experienced team has helped injured Ontarians pursue the compensation they deserve. Contact us for a free consultation or visit www.ddinjurylaw.com to learn more.

About Deutschmann de Koning Law

Deutschmann de Koning Law serves South-Western Ontario with offices in Kitchener-Waterloo, Cambridge, Woodstock, Brantford, Stratford and Ayr. The law practice of Robert Deutschmann and Nick de Koning focuses almost exclusively in personal injury and disability insurance matters. For more information, please visit www.ddinjurylaw.com or call us at 1-519-742-7774.