As of today, Canadians will find it harder to get away with impaired driving.
New rules that increase penalties and expand police powers to demand breath samples take effect across Canada.
Legislation, which passed in June at the same time as new rules for drug-impaired driving, is intended to curb injuries and death by helping police catch drivers with more than the legal limit of alcohol in their bloodstreams.
It gives police officers the right to ask for a breath sample from any driver they lawfully stop, lowering the bar from the previous legislation, which required that an officer have reasonable suspicion that a person had been drinking.
Toronto-based lawyer Michael Engel, who often defends those charged with impaired driving, predicts legal challenges.
Justice Minister Jody Wilson-Raybould has said she has "every expectation'' the law will be challenged in the courts, but noted that she's sure it'll pass the test.
Toronto police Sergeant Brett Moore said the lower standard for administering breath tests gives officers another tool in their belt to stop drunk drivers.