Impaired Driving: The Two-Hour Rule and Your Defences

Since December 2018, the Criminal Code provides that a person commits an offence if their blood alcohol concentration is equal to or exceeds 80 mg of alcohol per 100 ml of blood (the well-known 0.08) within two hours of ceasing to operate a conveyance. The rule applies to any mode of transport: automobile, boat, aircraft or railway equipment.

What if I drank after driving?

A defence exists, but the accused must establish three conditions:

they drank after they stopped driving;
at that time, they had no reason to expect to be required to provide a breath or blood sample;
their consumption is consistent with the measured blood alcohol concentration and with a blood alcohol concentration below 0.08 at the time of driving.

Two situations, two outcomes

Situation 1: After a night of heavy drinking, a driver hits a parked car and leaves the scene. A witness notes his licence plate. When the police arrive at his home, he has just poured himself a drink. His defence has little chance of success: after a hit-and-run, he had reason to believe he would be asked for a sample, and his blood alcohol concentration will far exceed what a single drink could explain.

Situation 2: A woman comes home sober after a long evening of babysitting, hits a snowbank while parking, and then has two drinks to unwind. A neighbour calls the police. Here, the defence may succeed: she drank after driving, nothing led her to believe she would have to provide a breath sample, and a calculation of her blood alcohol concentration (timing and quantity of drinks, alcohol content, elimination) can support her version of events.

These cases turn on precise details. The sooner you consult a lawyer, the easier it is to reconstruct the facts.

Need a criminal law lawyer?

Every case is different. Our lawyers will analyze your situation and explain your options. In criminal matters, acting quickly often makes a difference.

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Impaired Driving: The Two-Hour Rule and Your Defences