Many drugs, even those prescribed by a doctor or purchased over-the-counter, can impair your ability to drive safely. For example, smoking, vaping or eating cannabis can increase your risk of being involved in a motor vehicle collision. If you are unsure of whether it is safe for you to drive while taking your medication, talk to your doctor or pharmacist.

The Canadian Society of Forensic Science recently released a report stating that impairment from cannabis begins almost immediately and can last up to 6 hours or more, depending on factors such as THC levels and how it is consumed. Frequent high-dose THC users may experience even longer periods of impairment. However, since the effects of cannabis vary, there is no way to know exactly how long to wait before it is safe for you to drive. The best way to avoid impaired driving is to not take a chance. If you’re using cannabis, plan another way home.

What counts as impaired driving

Impaired driving means operating a vehicle (including cars, trucks, boats, snowmobiles and off-road vehicles) while your ability to do so has been compromised to any degree by consuming alcohol, drugs or a combination of the two.

Fully Licensed Drivers

Throughout Canada, the maximum legal blood alcohol concentration (BAC) for fully licensed drivers is to be under 80 milligrams of alcohol in 100 millilitres of blood, or 0.08. Driving with  a BAC of 0.08 or over is a criminal offence and the penalties are severe.

In Ontario, you will also face serious consequences if your BAC is between 0.05 and 0.08. This is commonly referred to as the “warn range.”

Zero tolerance for young, novice and commercial drivers

Young and Novice Drivers

Drivers age 21 or under and novice drivers of any age (with G1, G2, M1, or M2 licenses) must not have any presence of alcohol in their blood when behind the wheel. This is commonly referred to as the “zero BAC” or “zero tolerance” rule.

Young and novice drivers are prohibited from having any presence of cannabis in their system as well as other drugs that can be detected using  approved drug screening equipment. That means that Ontario has a zero tolerance approach to both alcohol and drugs for all young and novice drivers.

Commercial Drivers

As of July 1, 2018 drivers of vehicles requiring an A-F class licence, vehicles requiring a Commercial Vehicle Operator’s Registration (CVOR) and road building machines are prohibited from having any presence of alcohol in their blood when behind the wheel of these types of vehicles. These drivers are also prohibited from having any presence of cannabis in their system as well as other drugs that can be detected by an approved drug screening equipment.

Medical Cannabis Users

If a police officer is satisfied that you are legally authorized to use cannabis for medical purposes, you will not be subject to Ontario’s zero tolerance drug requirements for young, novice and commercial drivers. However, you can still face penalties and criminal charges if a police officer determines that your ability to drive has been impaired. Even if you have been authorized to use cannabis or another drug by a health care professional, it is your responsibility to ensure you are not impaired while driving.

Penalties for impaired driving

If police determine that you are driving while impaired you will face penalties immediately. You will also face additional consequences later if you are convicted in court. The penalties you face can vary depending on your age, licence type, the amount of alcohol or drugs in your system, and how many times you have been convicted.

Immediate Penalties

Penalties for a BAC in the Warn Range, Failing a Standardized Field Sobriety Test or Violating Zero Tolerance

If your blood alcohol concentration is 0.05 or higher, you fail a roadside sobriety test or you violate the zero tolerance requirements for young, novice and commercial drivers that begin on July 1, you will face:

First offence

  • 3-day licence suspension. This cannot be appealed.
  • $250 penalty

Second offence within 5 years

  • 7-day licence suspension (3-day suspension for commercial drivers). This cannot be appealed.
  • $350 penalty
  • You must attend a mandatory education program (for a second occurrence within 10 years)

Third and subsequent offences within 5 years

  • 30-day licence suspension (3-day suspension for commercial drivers). This cannot be appealed.
  • $450 penalty
  • You must attend a mandatory treatment program (for third and subsequent offence within 10 years)
  • You will be required to use an ignition interlock device for at least six months (for third and subsequent offence within 10 years)
  • You will need to undergo a mandatory medical evaluation to determine whether you meet the requirements for driving in Ontario (for fourth and subsequent offence within 10 years).

In addition to the penalties above, you will also face a $275 licence reinstatement fee each time your licence is suspended. Young or novice drivers may also be charged under the Highway Traffic Act and if convicted, you will face an additional suspension and fine.