With the holiday season upon us, Ontario police have begun making a concerted effort to ensure highway safety by proactively targeting impaired drivers. The linchpin of this effort is the annual Festive RIDE (Reduce Impaired Driving Everywhere) campaign , launched by police services across the province on November 20th and continuing until January 1st. The holiday-oriented campaign is a core component of Ontario Ride, an anti-impaired-driving program founded in 1977. The initiative relies on sobriety checkpoints to identify motorists who are driving under the influence (DUI) of alcohol and/or drugs, and public outreach to warn people about the dangers of impaired driving.
With Festive Ride now in full force, it seems like an appropriate time to consider the effectiveness of DUI checkpoints and highlight the facts and myths the public has about them. With a solid understanding of DUI checkpoints in Ontario, the DUI criminal defence lawyers of the Greater Toronto Area’s Mass Tsang law firm are well-positioned to tell you what you need to know. Let’s see what they have to say by considering their responses to the most frequently asked questions they hear from clients about DUI checkpoints and Ontario RIDE.
When asked about the success rate of DUI checkpoints, Mass Tsang managing partner Jeff Mass explains that their effectiveness can be assessed in two primary ways: the impaired driver detection rate and their deterrence value. The first is hard to quantify due to a relative lack of national and provincial checkpoint-specific data. Based on various municipal and regional studies, DUI checkpoints detect impairment in about 2% of drivers stopped on average. “While that rate might seem low,” says Jeff, “every impaired driver taken off the road marks a success.”
Jeff adds that DUI checkpoint effectiveness is probably much greater with its deterrence value. “Public outreach is a key component of DUI checkpoint programs across the country, with police warning drivers that they plan to be out in force manning checkpoints. This undoubtedly makes many drivers think twice about getting behind the wheel after they’ve consumed alcohol or drugs,” he concludes.
Jeff’s co-managing Mass Tsang partner, Robbie Tsang , says that while DUI checkpoints undoubtedly helped reduce the country’s impaired driving rates over the past two decades, mandatory alcohol screening (MAS) made them much more effective. “Before legislative changes were enacted in 2019, Canadian police needed probable cause to screen a driver for alcohol or drug impairment,” he says. “Whether at a sobriety checkpoint, during a traffic stop, or in any situation, an officer needed to identify reasonable grounds to demand screening, yet alcohol and drug impairment is not always apparent."
“The game changed in 2019, when the police were authorized to demand MAS of any driver,” he continues. “DUI arrests jumped that year due to mandatory screening and a rise in drug-impaired driving due to cannabis legalization. However, I believe that DUI arrest rates are again trending down as the motoring public — and many who may have previously considered driving while impaired — have become aware of MAS and what a powerful tool it is for police to identify and arrest drunk drivers.”
If you’ve heard that DUI checkpoints and MAS are unconstitutional, and, thus, open to courtroom challenges for violating Charter Rights, we can report that the Supreme Court of Canada upheld the legality of DUI checkpoints in its Dedman v. The Queen [1985] 2 S.C.R. 2 decision. In its 7-2 decision, the justices determined that sobriety checkpoints are a reasonable and limited infringement of Charter Rights based on the public interest in reducing impaired driving traffic deaths. Subsequent high court decisions have solidified their legality in relation to Charter Rights.
However, in R. v. Mellenthin [1992] 3 S.C.R. 615 , the Supreme Court established limits on the actions the police may take during sobriety checkpoints. In the absence of reasonable grounds to suspect other criminal activity conducted by vehicle occupants, police can only check the driver’s sobriety and driver’s license, as well as the vehicle’s ownership, insurance, and mechanical fitness. Police who go beyond these actions during a DUI checkpoint are violating the motorist’s Charter Rights.
As for MAS, provincial high courts have rejected Charter Rights challenges to the law in at least six cases, based on the same rationale that has upheld the legality of DUI checkpoints. To date, the Supreme Court has not yet agreed to hear a related case that might definitively settle the issue.
The technology used in approved screening devices (ASDs) for DUI checkpoints has undergone significant changes over the past two decades, enhancing their reliability and boosting impairment detection rates. Additionally, police departments nationwide are increasingly adopting oral fluid drug screening devices to detect drug impairment in drivers. However, despite advances in technology, readings from these devices cannot be used in court to prove a criminal DUI. Instead, the readings allow the police to demand additional breathalyzer or blood testing, which provides them with court-admissible evidence of impairment. Additionally, most provinces allow the police to administratively penalize drivers whose ASD results indicate a level of impairment below the legal criminal DUI threshold.
Whatever the technology, it’s essential to know that the law codifies the refusal of roadside screening at a DUI checkpoint, or additional breathalyzer or blood testing as warranted by ASD results, the same as a criminal DUI.
As lawyers, we cannot tell you whether the 1/2/3 rule about drinking will prevent you from getting a DUI at a sobriety checkpoint. The rule, based on the average person’s ability to metabolize one standard drink per hour, is as follows:
Holding to this rule is believed to keep most people under the legal blood alcohol concentration limit of 0.08%. However, it depends on keeping track of time, only drinking standard alcohol portions, and other factors. Additionally, it may not be effective at preventing a driver from breaching the 0.05% warn range, which could trigger police to issue administrative penalties, including license suspensions, fines, and vehicle impoundment.
We’ve covered the facts about DUI checkpoints and exposed a couple of myths, but let’s close by highlighting a couple of other common myths:
| Statement | Fact or Myth | Clarification |
|---|---|---|
| DUI checkpoints are illegal and violate Charter Rights | Myth | The Supreme Court upheld their legality in Dedman v. The Queen (1985) |
| Police must announce the location of all DUI checkpoints | Myth | Announcements are common for deterrence, but not required by law |
| You can refuse roadside screening without consequence | Myth | Refusal is treated as a criminal DUI |
| DUI checkpoints are more about catching impaired drivers than deterrence | Myth | Their main value is deterrence, especially during campaigns like Festive RIDE |
| Mandatory alcohol screening (MAS) helps officers detect impairment without visible signs | Fact | Enacted in 2019, MAS allows screening without suspicion |
| Oral fluid drug tests at checkpoints can result in criminal charges | Myth | These tests prompt further testing but aren’t court-admissible on their own |
| You have the right to talk to a lawyer before submitting to roadside screening | Myth | That right only applies after failure of roadside testing or upon arrest |
| Drivers can legally turn away from a checkpoint without consequence | Myth | Police can pursue and stop any vehicle evading a checkpoint |
If Greater Toronto Area police arrest you for DUI due to a sobriety checkpoint, consult with the experienced DUI criminal defence lawyers of Mass Tsang. With decades of experience defending our clients against DUI charges in Toronto, our expert defence team has won more than 1,200 cases, acheiving a 91% success rate. To schedule your free case evaluation, contact us today.
