Roadside Drug Testing

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The British Columbia Civil Liberties Association (BCCLA) is the oldest and most active civil liberties association in Canada. We regularly make submissions to governments, and intervene in the courts, on issues impacting civil liberties in Canada. For more information on the BCCLA, see our website at One of our key areas of concern is privacy rights. Another is due process. Roadside drug testing implicates both of these concerns, among others. Accordingly, we thank you for the opportunity to submit our position, which we think reflects that of many Canadians.

The BCCLA opposes driving while impaired for any reason. Moreover, even in the absence of a demonstrable link between drug use and driving impairment, the BCCLA opposes the use of any potentially impairing drugs in close temporal proximity to driving. However, the scheme proposed by the consultation document contains provisions that could significantly impact the liberty of Canadians, with little corresponding value added to the tools that police already have.

Police currently have a range of laws that allow them to deal with the problem of impaired driving. In British Columbia, and likely elsewhere, police can issue administrative suspensions that immediately remove unsafe drivers from the road. Police are trained to recognize behavioral symptoms of impairment and, ultimately, can charge a driver based on these observations. Finally, police can seek a warrant to obtain blood samples (or other bodily fluids) where reasonable and probable grounds for issuing the warrant exist. These existing mechanisms are both more effective and less costly than the scheme set forth in the consultation document.

As more fully described below, the consultation document sets out a non-validated procedure that significantly impacts civil liberties. Problematically, the consultation document itself lacks supporting detail in a number of areas, including the scope of the proposed drug testing. For example, no supporting evidence is provided on the critical issues of the accuracy of drug tests, the range of drugs that drivers are tested for and the ability of the tests to demonstrate actual impairment. What is clear, however, is that the legislative scheme set out in the document poses significant problems related to civil liberties.

The Consultation Document

As we understand it, the government proposes to implement a multi-stage process that would allow police to demand that motorists take part in roadside, and, ultimately, police station testing for drug impairment. This testing would include the requirement that drivers provide sweat, saliva, urine and/or blood samples for analysis.

The process outlined in the consultation document consists of several stages. The first stage is triggered when police suspect someone of driving while impaired, typically as a result of poor or erratic driving. Police then observe the driver and ask questions, in an attempt to determine impairment. Standardized field sobriety tests are performed and the driver is required to take a breath test. This breath test either indicates alcohol is present, or rules alcohol out as the cause of any potential impairment.

The next step is a roadside test for the presence of drugs. The consultation document is unclear about what this entails; either a saliva or sweat sample. Based on the results, the driver would be taken into custody and transported to the station. There, the driver would be subjected to further evaluation by “drug recognition experts” (DRE) and further testing. The driver could have blood drawn, or could be required to provide a urine sample. Ultimately, the driver would either be charged with driving while impaired, charged with another motor vehicle offence, or released.

The BCCLA objects to the implementation of the scheme proposed in the consultation document. As described, the proposed legislation poses several civil liberties problems. It is unduly invasive of privacy and will lead to an increase in the number of arrests and detentions of drivers without reliable evidence that the drivers are, in fact, impaired. DRE protocols are not infallible and, indeed, there is some evidence that the DRE examination process (including testing of bodily fluids) is susceptible to significant levels of false positive results. Given the inherent problems, more fully articulated below, that exist in the proposed legislative scheme the BCCLA believes that implementing the protocol described in the consultation document is a grave mistake.


The Privacy Problem

It goes without saying that drug testing is invasive of privacy. Urine tests, for example, require the driver to provide the specimen while being observed by police. This is a humiliating and often degrading experience. Blood tests are just as invasive, particularly because the proposed legislation could allow police to force an individual into providing a blood sample.

In addition, the results of the test has the potential to reveal much more than the presence of drugs in one’s system. Personal medical information, such as genetic predispositions to disease and whether an individual is pregnant, for example, can be revealed by drug tests. Moreover, blood samples can reveal the DNA of the driver, and it is currently unclear just how much information can be learned from DNA. What is clear, however, is that whatever is learned is intensely personal and private.

Because of the very personal nature of the information obtainable from bodily fluids, any legislation must be sensitive to the privacy rights of the drivers. At minimum, any legislation must contain clear language prohibiting the use of the bodily fluids for anything other than testing for the presence of drugs. The legislation must also mandate that the samples be destroyed after their utility as evidence of driving while impaired is exhausted. The BCCLA recommends that any legislation make it an offence to retain bodily fluid samples after the resolution of any charge arising from the incident that gave rise to obtaining the sample. In addition, it should be an offence to use the sample for any purpose other than testing for the presence of drugs.

Arrest and Detention

The consultation document envisions a scheme in which police could demand that motorists accompany them to the police station for further testing, based on the results of the roadside encounter. In other words, drivers will be arrested and detained. While the consultation document suggests that the length of the detention will typically be 45 minutes, the BCCLA is not confident in that estimate. The mere transport to the police station will take time, and the types of tests contemplated are numerous. it is also unclear when the right to counsel is triggered under the proposed scheme.

Moreover, any involuntary detention impacts the liberty of the citizen, irrespective of length. It is, for many, an extremely stressful experience. It is also inconvenient. What of the driver with passengers in the car, or the driver who must miss an important appointment as a result of an accusation of drug impairment – an accusation that is not proved simply because drug testing indicates that drugs are present in one’s system? As we discuss below, the roadside determination, even by trained DREs, is not always accurate.

Assumption in the Consultation Document About DRE Examinations

The consultation document contains a critical, but potentially faulty, assumption. The document indicates that, in order to understand the proposed legislative scheme, one must be familiar with the protocols for drug-impaired driving investigations. According to the consultation document: “If conducted properly, the investigation by trained officers will result in an accurate assessment of the suspect’s drug impairment….” (emphasis added). The assertion that testing will result in an accurate assessment is, at best, questionable but is presented as fact in the document. Indeed, it is far from certain that any drug impairment investigation, even by a trained officer, is able to accurately assess drug impairment.

The DRE process requires police officers to make determinations about impairment by borrowing from a range of scientific specialties: toxicology, psychology, pharmacology, ophthalmology, optometry and the neurologic and physiologic sciences. It is far from clear that police officers, even after DRE training, are equipped to make these type of determinations.[1]

Moreover, there appears to be little evidence to suggest that the DRE protocol has been generally established as a scientifically reliable means of proving what it seeks to prove – that an individual has ingested a particular class of illegal substance, which has then caused impairment. The BCCLA is unaware of, and the consultation document does not reference, any scientific studies demonstrating that the DRE protocol is both reliable and accurate.

Indeed, just the opposite appears to be true. The non-drug-test portion of the DRE examination is susceptible to error. For example, part of the examination is a test of the driver’s blood pressure and heart rate. The stress of arrest itself can lead to a higher pulse and higher blood pressure – irrespective of drug use. Other physical symptoms of medical conditions can cause a faulty diagnosis by a DRE. In the United States, the basis for the DRE protocol identified in the consultation document, several lawsuits have been brought against police for violating citizens’ constitutional rights after a DRE made a conclusion that a driver was impaired when, in fact, the person had ingested no drugs.[2]

The BCCLA does not oppose training officers to detect signs of impairment. Indeed, we support removing impaired drivers from the road – whatever the cause of the impairment. Notably, police are not able to charge someone with impairment unless that impairment was caused by drugs or alcohol – which leaves a wide range of impairing behavior (lack of sleep, use of cell phones, etc.) allowable, in effect. Police can, in BC and likely elsewhere, use other provisions of the Motor Vehicle Act to temporarily remove drivers from the road by issuing a 24 hour ban – irrespective of whether they can substantiate drug impairment sufficiently to obtain a conviction. We object, however, to legislation that allows police to detain citizens and require sample of bodily fluids on the basis of DRE assessments that lack sufficient indicia of accuracy.

Relevance of Information Obtained From Bodily Fluid Drug Testing

Even if the non-bodily-fluid-testing portion of the DRE examination is able to provide a correlation to drug use (ie, the DRE’s determination of drug impairment is supported by the presence of drugs in the suspect’s system), the key question of impairment is not answered. In other words, that a DRE concludes that a driver has used cannabis, and later drug testing reveals cannabis in that driver’s system, is not evidence that the driver was impaired by cannabis at the time he or she was driving.

Of course, if someone is impaired by drugs, they should not be driving. And the BCCLA opposes the use of any impairing drugs prior to operating a motor vehicle. However, the invasive testing proposed by the consultation document will not answer the critical question: did drug use cause impairment?

As an initial matter, the presence of drugs (drug metabolites, to be precise) in one’s system does not tell police whether the driver was under the influence of drugs while driving. One can consume drugs hours, or days, prior to a drug test and still test positive. Thus, we have a problem with the issue of temporal proximity of use to driving. The threshold question (was the driver “on drugs” while driving), then, is simply not answered by testing sweat, saliva, urine or blood.

Moreover, even assuming that tests could show whether the driver was “on drugs,” the critical question still remains: did the drugs impair the person’s ability to drive? The scientific data is far from clear. For example, studies attempting to prove a link between cannabis use and significant driving impairment have been unable to adequately demonstrate a link.[3] Some studies have even concluded that drivers under the influence of cannabis are less likely to cause motor vehicle accidents than drivers who have not consumed any substances.[4] This is because cannabis tends to make a user drive more slowly and to take less risks on the road (the opposite effect than alcohol, which tends to cause speeding and risky driving behavior).[5] Absent a reliable scientific link between drug use and actual impairment, invasive searches of one’s bodily fluids (and the accompanying detention necessary to effectuate the tests) are inappropriate, particularly given that the police already have the ability to remove drivers from the road based on their actual driving activity.

Ultimately, the only real basis for judging impairment from drugs is behavioral. The mere presence of drugs in one’s system does not equate to impairment. At present, the indicia of impairment rests on behaviors; was the driver driving badly, do they demonstrate a lack of physical coordination, are they mentally cognizant of their surroundings, etc. Police, now and in the past, use their observational powers to assess the question of whether someone should be on the road and can (at least in BC, and likely in most jurisdictions) remove unsafe drivers immediately. The result of a drug test adds negligible value, at best, to the determination of impairment. Indeed, there is a real possibility that drug testing adds a veneer of scientific credibility to an officer’s determination of impairment when, in fact, the test actually has little relevance to the ultimate question.

There is also a problem with the judicial relevance of drug test results. It seems unlikely that a court would be able to accept the result of a bodily fluid test as determinative of the fact of impairment, particularly in the context of a criminal matter requiring proof beyond a reasonable doubt. Given the problems of relevance, it makes little sense to implement a legislative scheme that is expensive (in terms of training costs, officer time, citizen time, judicial resources that will be consumed with battles of experts, and the like), invasive of privacy and of little probative value.

The Problem of False Positives

All drug testing is susceptible to error. Legal medications can cause false positives for illegal drugs. Poppy seeds can cause false positives for opiates. Some over the counter anti-inflammatory medication (such as ibuprofen) can cause false positives for cannabis. More than 100 prescription drugs can cause false positives.[6] [7] In a comprehensive fifty-three month study of 500 DRE decisions, the DRE determinations were supported by bodily fluid testing only 83.5% of the time – indicative of a significant rate of false positives.[8] While the rate of false positives can be minimized by repeat testing, with enhanced screening procedures, this is small consolation for the driver that has been wrongly arrested and charged on the basis of a roadside, or station-house, drug test.

On a practical level, the problem of false positives is a significant obstacle to the admissibility of drug test results in court. Accordingly, any positive result from a roadside or police station test will have to be verified by further, costly, testing performed by qualified technicians, utilizing protocols that minimize the incidence of false positives.


As noted above, the BCCLA opposes driving while impaired for any reason. However, the scheme proposed by the consultation document contains provisions that could significantly impact the liberty of Canadians.

The consultation document proposes a legislative scheme that is extremely intrusive of privacy and will almost certainly result in the arrest and detention of drivers that have done nothing wrong. Given that, the onus should be on proponents of roadside drug testing to prove that it is accurate, relevant and that the potential for abuse is minimized. This case has not been made. The DRE protocol is susceptible to false positives at each step. Testing of bodily fluids does not provide evidence of when the drugs were used. Moreover, even if the process were 100% accurate at determining whether a driver had used recently used drugs, the proposed scheme fails to answer the critical question of whether the drug use actually caused impairment of the driver’s ability to operate a motor vehicle. In other words, drivers will be subject to arrest, detention and forcible testing of bodily fluids but the ultimate question of impairment will not be proved by these procedures.[9] For these reasons, the BCCLA strongly opposes the legislative scheme set forth in the consultation document.


Kirk Tousaw

Policy Director

[1] That police will make these types of determinations will undoubtedly lead to evidentiary disputes in court. Valuable court time will be taken up by forensic battles and expert testimony. The consumption of court time, as well as police and forensic expert resources, are costs that will ultimately be passed on to the taxpayer.

[2] See, for example, Foote v. Spiegel, 36 F Supp 2d 1320 (D. Utah 1999) (Police concluded, based on DRE protocol, that Foote was impaired by drugs. Instead, she had a neurological disorder. Ms. Foote was arrested and strip searched based on the faulty DRE conclusions); Luzzi v. Mack, No. 95 Civ 9720, 1998 WL 150496 (SDNY 1998) (DRE instructor, in consultation with director of NY DRE program, arrested Luzzi for drug impaired driving. Subsequent drug tests revealed no drugs in Luzzi’s system. Luzzi sued for violation of her constitutional rights); Hughes v. Allen, 899 F2d 1225 (9th Circuit 1999) (Hughes suffered a stroke, but stopped his vehicle in the freeway center divider. A DRE examined Hughes and concluded that he was impaired by opiates. Later drug testing revealed that Hughes was not using opiates. Huges sued for violations of his constitutional rights.).

[3] “The foremost impression one gains from reviewing the literature is that no clear relationship has ever been demonstrated between marijuana smoking and either seriously impaired driving performance or the risk of accident involvement.” Robbe & O’Hanlon, 1993 (sponsored by the US National Highway and Traffic Safety Administration).

[4] Longe, et al, “The Role of Alcohol, Cannabinoids, Benzodiazepines and Stimulants in Road Crashes” University of Adelaide 2000 (online at

[5] “Instead of proving that drug-taking while driving increased the risk of accidents, researchers found that the mellowing effects of cannabis made drivers more cautious and so less likely to drive dangerously.” as reported in The Times (UK) 13 Aug 2000.

[6] STAT America (drug test laboratory) online at

[7] Canadian Human Rights Commission, “Drug Testing Consultation Paper” online at

[8] Eugene V. Adler & Marcelline Burns, Drug Recognition Expert Validation Study: Final Report to Governor’s Office of Highway Safety, State of Ariz. (June 1994). Notably, this study is often cited as supporting the proposition that the DRE protocol is successful. The BCCLA feels that an 83% “success” rate is far from indicative of an accurate testing protocol, particularly when a driver will face arrest, removal of driving privileges and criminal charges as a result of a “positive” test.

[9] Of course, the state of the science on the accuracy of the DRE protocol, the accuracy of drug testing, and its ability to determine when drugs were used and whether that use caused impairment may change. If so, reconsideration of the proposed legislation may be appropriate. We are not, however, at that point.