While proponents of the new rule call it a step in the right direction, it's not yet clear how effective the measure has been in deterring young people from drinking and getting behind the wheel.
Since the legislation was enacted on April 15, Quebec drivers under age 22 caught with a blood-alcohol level over zero face some of the toughest drunk-driving penalties in the country — an immediate three-month suspension of their licence, fines up to $600 and a loss of four demerit points.
Despite the stiff penalties, some young people are still choosing to drink and drive. In an undercover operation, Montreal's La Presse newspaper found that more than half the young designated drivers they tested had some alcohol in their system while leaving local bars.
Stephane Maurais, a director at Alcohol Prevention Canada, said he was surprised at the number of young people who were over the limit.
He said that while some weren't aware of the new law, others simply refused to accept it.
"In their mind, having one or two beers is something acceptable," he said. "When you are 18 or 19 years old, you want to challenge these kind of things."
Young people who drink and drive are at high risk of collision — 45 per cent of young drivers who are killed on the road had been drinking, compared to the average of 37 per cent for all drivers, according to Mothers Against Drunk Driving.
"Unfortunately, younger drivers are way over-represented in statistics of death and injuries," said MADD Quebec chapter spokesperson Marie-Claude Morin. "They cause a lot of damage on the roads."
Ontario introduced a similar policy to Quebec's in 2010, but the penalties are less severe. Ontario drivers under age 22 with any alcohol in their system are subject to an immediate licence suspension of just 24 hours. If convicted, they face fines of up to $500 and a 30-day licence suspension.
As of March 31, there have been 709 convictions for drivers aged 21 and under for violating the zero-tolerance policy in Ontario.
"I think Ontario, if it had to do it again, it would have gone with more severe penalties," said MADD's chief executive, Andrew Murie.
A spokesman for the Ontario Ministry of Transportation said is still too early to assess the impact that the zero-alcohol rule has had in that province. However, spokesman Bob Nichols said the 2010 legal change was a necessary step in deterring young drivers from drinking and driving.
Canadian provinces that have implemented the legislation have, according to sources MADD says it has consulted, seen percentage decreases in the double digits for impaired driving accidents in youths. The decreases have ranged from 20 to 25 per cent, according to Murie — although MADD could not point to any publicly available statistics.
Murie is hoping Quebec will see a decrease of at least 10 to 15 per cent.
For older drivers in the province, however, the legal blood alcohol level remains at 0.08 per cent — a limit critics say is still too high.
Quebec is the only province in Canada that doesn't have measures to suspend licences for drivers with a blood-alcohol level of over .05 per cent.
The proposed measure of lowering the blood alcohol limit to .05 per cent was "a done deal" under legislation originally introduced by the Quebec government, said Claude. That fell by the wayside when then-transport minister Sam Hamad heeded an appeal from bar and restaurant owners who worried that such a measure would kill their industry.
"There's a very strong lobby for alcohol in Quebec," said Claude. "If you decide to drink that's your problem, that’s your decision. But we don't want people mixing drinking with driving."
The .05 blood-alcohol limit has been established in more than 90 countries, including most of Europe, according to Claude.
"There is no reason why Quebec is so behind everyone else," she said.