drug testing is increasing but does not work

The Government is considering making changes to New Zealand’s drug driver testing and enforcement regime. Read NORML’s submission to NZTA’s discussion document here.

28 June 2019

Drug Driving Consultation
Ministry of Transport
PO Box 3175

By email drugdrivingconsultation@transport.govt.nz

Submission on NZTA discussion document on enhanced drug impaired driver testing

This submission is from NORML New Zealand Inc. We would like to discuss this issue further if there is an opportunity.


NORML New Zealand is a non-profit membership-based society, incorporated in 1980. Our mission is to move public opinion sufficiently to legalise the responsible use of cannabis by adults, and to serve as an advocate for consumer safety. NORML’s Principles of Responsible Cannabis Use[1] includes not driving while impaired:

The responsible cannabis consumer does not operate a motor vehicle or other dangerous machinery impaired by cannabis, nor (like other responsible citizens) impaired by any other substance or condition, including some medicines and fatigue.

Although cannabis is said by most experts to be safer than alcohol and many prescription drugs with motorists, responsible cannabis consumers never operate motor vehicles in an impaired condition. Public safety demands not only that impaired drivers be taken off the road, but that objective measures of impairment be developed and used, rather than chemical testing.

Responses to questions in the discussion document

QUESTION 1: Do you think that roadside drug screening is a good option for deterring drug driving and detecting drug drivers? Are there other options not mentioned in this Discussion Document?

We support the intention to make driving safer and to remove impaired drivers from our roads. The challenge is to accurately deter and detect impaired drivers while not erroneously capturing non-impaired drivers. This applies to both roadside testing of drivers and blood testing of hospitalised drivers – the two elements of drug-driving enforcement in New Zealand.

Different people have different tolerances for different substances. In the case of cannabis, it can still be in the system weeks after consumption. That’s why roadside screening cannot be based merely on the presence of drugs.

We support enhanced use of the current Field Sobriety Test, with more training for officers. There should be dash-cams installed in every police car so the FST can be replayed if necessary.  This would provide an impartial visual recording of any impairment and reduce concerns by law enforcement officers that the FST alone means they must establish impairment in court.

We also support non-invasive technology-based solutions to better measure impairment with a handheld device fitted with various sensors and connectivity, such as developing an app that can be used on any smart phone – by law enforcement and by drivers to self-test. For an example see the My Canary[2] app developed by NORML to give consumers the scientific information they need to honestly and accurately evaluate their personal performance.

Additional funding for training, dash cams and developing new technology could come in part from levies on the sale of legal cannabis products for adult use. Funding should also used to support development of new technology.

QUESTION 2: Do you support oral fluid screening for roadside drug testing of drivers? Are there other options not mentioned in this Discussion Document that could be considered?

No. Oral fluid tests are unreliable, inconvenient, expensive and of dubious benefit. The proposed oral fluid testing could be a significant inconvenience to drivers and impractical for law enforcement if any proposed tests take any longer than a moment to complete. Expecting police officers to handle bodily fluids is very invasive and subject to cross contamination with danger of spreading germs if the sanitation habits are not ‘up to scratch’. There will also be significant financial costs to carry out any testing programme, with each test costing many times what it costs to perform an alcohol breath test.

These costs must be weighed against the relative benefits any proposed testing would bring; saliva (oral fluid) tests are unreliable, expensive, do not detect drugs highly indicated in impairment such as synthetic cannabinoids or opiates, and are impractical to be deployed for checkpoints.

QUESTION 3: Is it reasonable to delay drivers by 3 to 5 minutes to administer a roadside drug screening test, in order to detect drug drivers and remove them from the road?

The discussion document notes at s22-29 that detaining drivers potentially breaches s21, s22 and s25(c) of the Bill of Rights Act 1990, which affirms the right to be free from arbitrary detention, unreasonable search and seizure, and to be presumed innocent until proven guilty.

We consider these breaches to not be reasonable or justified in the case of oral fluid tests, given the available evidence points to limited reliability from current testing devices including high rates of both false positives and false negatives; the very limited range of substances that are detected; and in the case of cannabis the lack of correlation between detection and impairment.

However, a similar delay to administer a FST could potentially be better justified, given a FST is a more accurate predictor of impairment, will detect impairment from all causes (drugs, alcohol, fatigue, distraction, psychosis etc), and may take just a few minutes to ascertain.

QUESTION 4: Is a presence-based, zero-tolerance approach to drug driving, where presence of a drug is sufficient for an offence, appropriate for New Zealand?

No. Many New Zealanders use cannabis regularly or on occasion. They may have cannabinoids or metabolites in their bodily fluids whether they are impaired or not. They may also have legal access to medicinal cannabis products – and if the 2020 cannabis referendum passes, legal access to other cannabis products for adult use.

QUESTION 5: Should there be legal limits for some drugs?

Yes. As with alcohol there should be a legal limit for cannabis, because:

  • The mere presence of cannabinoids or metabolites in bodily fluids is not an accurate predictor of impairment;
  • Impairment from cannabis is unlikely to occur at low levels; and
  • Cannabis can be legally consumed now (for medicinal purposes, in accordance with the prescriber’s instructions) and if the 2020 cannabis referendum passes cannabis will be legally consumed by hundreds of thousands of adult New Zealanders. It would be untenable to have a zero-limit for cannabis.

We suggest considering the level adopted by the US state of Colorado which is 6ng of THC per ml of blood, and the work of Grotenhermen et al, who noted:

“A comparison of meta-analyses of experimental studies on the impairment of driving-relevant skills by alcohol or cannabis suggests that a THC concentration in the serum of 7-10 ng/ml is correlated with an impairment comparable to that caused by a blood alcohol concentration (BAC) of 0.05%. Thus, a suitable numerical limit for THC in serum may fall in that range.”[3]

QUESTION 6: If roadside drug screening was introduced, which of the three approaches discussed above do you prefer?

 Testing under the current ‘good cause to suspect’ criterion

 Targeted testing following an incident or a driving offence

Random roadside drug screening, along the lines of the current breath alcohol testing model.
Are there other approaches that should be considered?

We support enhancing the current testing under the ‘good cause to suspect’ criterion. This should include:

  • training all law enforcement officers to perform the Field Sobriety Test;
  • ensuring all law enforcement officers are better prepared and supported to prosecute cases of impairment;
  • dash cams on all patrol cars to objectively record any impairment for later replay;
  • potential use of an oral fluid testing device only following a failed FST and as an initial screen;
  • evidential confirmation with a blood test, with a legal limit for THC that correlates with impairment (see Grotenhermen et al).

QUESTION 7: If random drug screening was introduced, do you think it is a reasonable and proportionate response to the harm of drug driving? Are there circumstances in which it would be more or less reasonable?

No. There is insufficient evidence to support the deployment of random drug screening for all drivers. This would:

  • breach the Bill of Rights;
  • be inconvenient to unimpaired drivers going about their business;
  • be costly;
  • take law enforcement officers away from more effective duties;
  • be made worse if blood, urine, hair or to a lesser extent saliva were taken;
  • be made better if a more-accurate and less-invasive FST were performed.

QUESTION 8: What criteria should be used to determine if a drug is included, or excluded, from drug screening?

This is very complex, and many factors should be considered. At a minimum these should include all the following:

  • Does it cause impairment?
  • Is it widely used?
  • Can it be detected accurately?
  • Does detection correlate with impairment?
  • Cost benefit – is it worth it?
  • Popularity with drivers – being “tough” vs inconvenience
  • Compliance by drivers – can it be avoided?
  • Unintended consequences – is risky behaviour deferred or shifted elsewhere?
  • Would screening achieve anything other than “sending a message”?
  • Is it used medically or otherwise legally?

QUESTION 9: What regulatory process should be used to specify the drugs that are identified for screening?

Specifying drugs that are identified for roadside screening, if it were to occur, would potentially affect every New Zealander and as such must be fully considered by Parliament with the proper scrutiny and opportunity for consultation that this deserves. Any further changes should also be via the full legislative process, like with changes to roadside screening for alcohol.

QUESTION 10: Should illicit and prescription drugs be treated differently?

No – except for below.

QUESTION 11: Should there be a medical defence for drivers who have taken prescription drugs in accordance with a prescription from a medical professional?

Yes. Such drivers are behaving legally and under direction.

QUESTION 12: If oral fluid testing was introduced in New Zealand, do you think there should be a requirement for a second drug screening test following a failed first test? Do you prefer another option for screening drivers?

Yes, any oral fluid test should only be considered a screen and there should be a requirement to confirm this with a proper evidential test. This should be a blood test until non-invasive technology is developed. However, rather than perform oral fluid tests we support enhanced use of the Field Sobriety Test, as discussed elsewhere.

QUESTION 13: Do you think that drug driving offences should be confirmed with an evidentiary blood test? If not, what evidence should be required to establish an offence of drug driving?

Yes. A blood test is the most accurate confirmation of current use, as opposed to detecting past or inactive residues in urine, hair or saliva. We suggest considering the level adopted by the US state of Colorado which is 6ng of THC per ml of blood, and the work of Grotenhermen et al, who noted:

“A comparison of meta-analyses of experimental studies on the impairment of driving-relevant skills by alcohol or cannabis suggests that a THC concentration in the serum of 7-10 ng/ml is correlated with an impairment comparable to that caused by a blood alcohol concentration (BAC) of 0.05%. Thus, a suitable numerical limit for THC in serum may fall in that range.”[4]

However, we also note that many people consider giving blood is invasive and carries a risk of infection and cross contamination.

QUESTION 14: Do you think an infringement offence (an instant fine and demerit points) or a criminal penalty (mandatory licence qualification, fines and possible imprisonment) is appropriate for the offence of drug driving?

If impairment is proven, an infringement offence is appropriate for drug driving offences. We assume any other penalties such as mandatory licence qualification, fines and possible imprisonment would still apply to any other offences a driver may be charged with.

If an FST finds no impairment, there should be no infringement offence or criminal penalty regardless of the presence of any drugs.

QUESTION 15: Is there any other penalty or action in response to the offence of drug driving that you think should be considered?

Education works:

  • Ensure awareness about impaired driving is part of driver licencing, training and renewals;
  • Support credible advertising campaigns that are based on evidence not scaremongering;
  • Provide drivers with clear guidance such as not driving within two hours of consuming cannabis

Reach out to those most at risk:

  • provide outreach to consumer groups and at-risk subgroups of drivers;
  • facilitate “dial a driver” campaigns for more than just pubs

QUESTION 16: Do you think it is reasonable to penalise drivers who have used drugs, but may not be impaired?

Absolutely not. This suggestion goes against modern evidence-based drug policy and is an anachronism from the bad old days of punishment based on morality. We assume this is asked merely to provide an opportunity to agree that it is in fact not reasonable to penalise drivers who have used drugs but may not be impaired.

QUESTION 17: Do you have anything else you would like to say about drug driving?

We note the available evidence regarding impairment relating to cannabis use is inconclusive rather than strongly pointing to causality. Some studies show impairment from cannabis use while others show little or no impairment, and this is itself significant: if there was a clear, incontrovertible, effect of cannabis causing impairment then we think more studies should show this and there would be much fewer showing little or no impairment. It is not so clear cut as the discussion document presents.

We agree impaired driving is an issue that should be addressed separately to, and in advance of, the cannabis referendum to be held at the 2020 election. We agree it makes sense to resolve the matter before the referendum and signal that this situation is in hand no matter how the country votes in that referendum.

Yours faithfully,

Chris Fowlie
for NORML New Zealand Inc, Board of Directors


EMCDDA, Driving Under the Influence of Drugs, Alcohol and Medicines in Europe — findings from the DRUID project. Lisbon, December 2012. http://www.emcdda.europa.eu/publications/thematic-papers/druid_en

Grotenhermen, F. et al. Developing limits for driving under cannabis. Addiction. 2007 Dec;102(12):1910-7. Epub 2007 Oct 4. https://www.ncbi.nlm.nih.gov/pubmed/17916224

NORML New Zealand Inc, Principles of Responsible Cannabis Use, https://norml.org.nz/about/responsible-use/

Transform Drug Policy Foundation, How to Regulate Cannabis: A Practical Guide (2nd Ed), 2016

[1] https://norml.org.nz/about/responsible-use/

[2] https://blog.norml.org/2015/07/15/canary-app-permits-marijuana-consumers-to-gauge-their-personal-performance/

[3] Grotenhermen, F. et al. Developing limits for driving under cannabis. Addiction. 2007 Dec;102(12):1910-7. Epub 2007 Oct 4. https://www.ncbi.nlm.nih.gov/pubmed/17916224

[4] Grotenhermen, F. ibid.