What is the Two-Hour Rule for Impaired Driving?
How Canada’s two-hour rule can affect an impaired driving charge in Ontario.
In a case of impaired driving the two-hour rule allows a driver to be charged based on the amount of alcohol in their blood within two hours after driving.
This means you may still face an impaired driving charge even if the police did not test your blood alcohol level until after you stopped driving. The timing of the breath tests, when you last drove, and what happened during those two hours can all become important parts of the case.
As a Toronto criminal lawyer Nicholas Charitsis has been helping drivers charged with drinking and driving charges and DUI offences for more than 25 years. Nick’s criminal practice has been focused on DUI law throughout that time and the results are represented in the hundreds of 5-Star Google reviews from his clients.
Where you’re looking for an experienced DUI Lawyer call Nicholas Charitsis at 416-731-7113.
How Does the Two-Hour Rule Work?
The two-hour rule can be confusing because you do not have to be sitting behind the wheel when the police find that your blood alcohol concentration is over the legal limit.
Under section 320.14(1)(b) of the Criminal Code, it is an offence to have a blood alcohol concentration of 80 mg or more per 100 mL of blood within two hours after you stop driving. (Department of Justice Canada)
In simple terms, you can stop driving and still be charged with Over 80 based on your blood alcohol level during the next two hours.
What Does “Within Two Hours of Driving” Mean?
Think of it as a two-hour clock that starts when you stop driving.
For example:
- You stop driving at 11:00 p.m.
- Police arrive at 11:30 p.m.
- You are taken to the police station.
- You provide breath samples at 12:15 a.m.
- Your breath test shows a blood alcohol concentration of 80 mg or more.
Even though you were tested more than an hour after you stopped driving, the breath test was still taken within the two-hour period. The result may therefore be used to support an Over 80 charge.
This is the part many people find surprising. The Crown does not necessarily have to prove that your blood alcohol concentration was over 80 at the exact moment you were driving. The law specifically makes it an offence to be at or above 80 within two hours after you stop driving. (Department of Justice Canada)
What If You Drank Alcohol After You Stopped Driving?
This is where the two-hour rule becomes more complicated.
Suppose you drove home and then had several drinks. Police arrived later and your breath samples showed that you were over 80. The breath-test result does not necessarily mean you were over 80 when you were driving.
The Criminal Code has an exception for certain situations where alcohol was consumed after driving. To qualify, the law requires all three of the following:
- You consumed alcohol after you stopped driving.
- You had no reasonable expectation that you would be required to provide a breath or blood sample.
- The evidence about your alcohol consumption and blood alcohol concentration is consistent with your blood alcohol concentration having been below 80 when you were driving. (Department of Justice Canada)
Simply saying that you had a drink after driving does not automatically provide a defence. The timing and evidence must support what happened.
Why Is the Timeline So Important?
When our impaired driving lawyers review a case involving the two-hour rule, we want to know exactly what happened and when.
We look at:
- When you stopped driving.
- When you had your last drink before driving.
- Whether you drank alcohol after you stopped driving.
- When police arrived.
- When the breath demand was made.
- When you arrived at the police station.
- When each breath sample was taken.
- What the breath-test results showed.
Putting these events into the correct order can help determine whether the two-hour rule applies and whether there are problems with the Crown’s evidence.
Why Was the Two-Hour Rule Added?
The two-hour rule was added to deal with a problem that could happen when someone drank alcohol after they stopped driving but before the police tested them.
In the past, the Crown generally had to prove that a driver’s blood alcohol concentration was over the legal limit while they were driving. This could create problems when there was a delay between driving and the breath tests.
The current law focuses on your blood alcohol concentration within two hours after driving.
Can Police Test You After You Have Stopped Driving?
Yes. Police may investigate and obtain breath samples after you have stopped driving. For example, an investigation could begin after an accident, after someone reports a suspected impaired driver, or after police locate a driver at another location.
The important point is that going home or getting out of the vehicle does not necessarily end the possibility of an Over 80 charge.
Police may still investigate:
- When you were driving.
- When you stopped driving.
- Whether you drank alcohol before or after driving.
- When the police first contacted you.
- When the breath samples were obtained.
- What your blood alcohol readings were.
This is why the two-hour rule can be important in cases where the police did not stop the driver on the road. The exact timeline can become a major part of determining whether the Crown can prove the charge.
Can You Be Charged If Police Test You More Than Two Hours After Driving?
Yes. A breath test taken more than two hours after you stopped driving does not automatically mean the charge will be dismissed.
The two-hour rule describes the blood alcohol level the Crown must prove. It does not mean police lose the ability to investigate or obtain breath samples once two hours have passed.
What Happens If the Breath Tests Are Taken After Two Hours?
When breath samples are taken outside the two-hour period, the case becomes more complicated for the police.
The Crown may try to use the later breath-test results, along with other evidence, to prove what your blood alcohol concentration was within two hours after you stopped driving.
This may involve evidence about:
- The time you stopped driving.
- The time each breath sample was taken.
- Your breath-test results.
- When and how much alcohol you consumed.
- Whether you ate food before or after drinking.
- The amount of time between driving and testing.
- Expert evidence about what your blood alcohol concentration may have been earlier.
Why Can a Toxicologist Be Important?
In some cases, a toxicologist may be asked to review the breath-test results and the timeline.
A toxicologist can consider the alcohol you consumed, the timing of your drinks, your breath-test readings and other relevant information. The expert may then provide an opinion about what your blood alcohol concentration could have been at an earlier time.
Our impaired driving lawyers can review whether expert evidence is needed and whether the Crown can reliably prove that your blood alcohol concentration was 80 mg or more within two hours after you stopped driving.
How Can the Two-Hour Rule Be Used in Your Defence?
The two-hour rule does not mean that a breath test showing 80 mg or more automatically proves the charge. Our impaired driving lawyers look closely at the timeline and the evidence to determine whether the Crown can prove that your blood alcohol concentration was over the legal limit within two hours after driving.
Depending on what happened, possible defence issues may include:
- Timing of the breath tests – We review when you stopped driving and exactly when each breath sample was taken.
- Drinking after driving – If you consumed alcohol after you stopped driving, we examine whether the exception in the Criminal Code may apply.
- Delayed breath testing – When testing takes place more than two hours after driving, the Crown may need additional evidence to establish your blood alcohol concentration during the two-hour period.
- Problems with the Crown’s timeline – Police reports, witness statements, video and other evidence may raise questions about when you were actually driving.
- Toxicologist evidence – An expert may be able to assess the breath-test results, drinking history and timing to determine whether the Crown’s conclusions about your blood alcohol level are reliable.
Every case depends on its own facts. A difference in timing, what happened after you stopped driving, or how the breath-test evidence is interpreted can change the case.
If you’ve been charged with impaired driving or Over 80, call Nicholas Charitsis at 416-731-7113 to discuss what happened and how we can help you.
Frequently Asked Questions About the Two-Hour Rule
1. What is the two-hour rule for impaired driving in Ontario?
The two-hour rule means you can be charged with Over 80 if your blood alcohol concentration is 80 mg or more per 100 mL of blood within two hours after driving. The Crown does not always have to prove that you were over 80 at the exact moment you were behind the wheel.
2. When does the two-hour period start?
The two-hour period generally starts when you stop driving or stop having care or control of the vehicle. For example, if you stopped driving at 10:00 p.m., the two-hour period would run until midnight. Establishing the exact time you stopped driving can therefore be an important part of the case.
3. What if I drank alcohol after I stopped driving?
Drinking after you stopped driving does not automatically prevent an Over 80 charge. However, the Criminal Code contains an exception for certain situations involving alcohol consumed after driving. Whether it applies depends on why you drank, whether you reasonably expected to provide a breath or blood sample, and whether the evidence is consistent with your blood alcohol concentration being below 80 while you were driving.
4. Can I still be charged if my breath test was taken more than two hours after I stopped driving?
Yes. Passing the two-hour mark does not automatically end the investigation or prevent a charge. When testing occurs later, the Crown may rely on the breath-test results and other evidence to try to establish what your blood alcohol concentration was within two hours after driving. The timing and reliability of that evidence can become important defence issues.
5. How can an impaired driving lawyer challenge the two-hour rule evidence?
Our impaired driving lawyers can examine when you stopped driving, when you consumed alcohol, when police arrived, when the breath samples were taken and what the test results showed. We may also consider whether toxicologist evidence is needed. The issue is whether the Crown can prove beyond a reasonable doubt that all the legal requirements of the charge have been met.
About the Author – Impaired Driving Lawyer Nicholas Charitsis
Nicholas Charitsis is a Toronto criminal defence lawyer and former Crown Attorney with more than 25 years of experience defending impaired driving charges in Ontario. His practice focuses on impaired driving, Drive Over 80, breathalyzer refusals, care and control, and other DUI-related driving charges.
His experience in DUI investigations allows him to identify legal issues involving breath testing, police procedures, Charter rights, disclosure, and whether the Crown Attorney can prove an impaired driving charge beyond a reasonable doubt. He has successfully defended impaired driving cases involving reasonable doubt, breathalyzer evidence, medical issues, identity, and whether the accused intended to drive.
Nicholas also serves as Chair of Ontario committees involved in recommending candidates for judicial and Justice of the Peace appointments. His combination of courtroom experience, former Crown experience, and more than 25 years practising criminal law provides clients with experienced advice when deciding how to fight an impaired driving charge.
