SSDP Aotearoa New Zealand Submission on the Land Transport (Drug Driving) Amendment Bill 2024

Students for Sensible Drug Policy New Zealand (SSDP) is a student and youth focused group with a vision of ‘An Aotearoa free from drug related harm’. We have chapters in Ōtepoti / Dunedin and Tāmaki Makaurau / Auckland. As our membership is primarily made up of students and academics, we believe strongly that political decisions should be backed by science and evidence. We are writing to you in response to the Land Transport (Drug Driving) Amendment Bill. SSDP is opposed to this bill.

SSDP supports measures to increase road safety, and to reduce impaired driving of all types, including from alcohol and other drugs. However, we believe that the understanding of the relationship between body drug concentrations and driver impairment, and the efficacy of oral drug tests is not currently adequate to enable the establishment of a fair roadside drug testing regime. It is our understanding that roadside tests used to identify driver impairment are very limited and inadequate for use in the proposed context. Further, we find the proposed quota system, and its inconsistencies with the Bill of Rights Act as identified by the Attorney General, highly problematic. The proposed bill is likely to infringe on the rights of everyday kiwis, particularly those who use drugs, and those belonging to minority ethnic groups who already face disproportionate levels of policing (Crossin et al. 2023). We outline specific concerns in more detail below.

Drug concentration vs impairment:

Cannabis is the most commonly used substance by Kiwis which is included in the original drug driving legislation (Land Transport (Drug Driving) Amendment Act 2022). However, we identified several oversights in this bill that seem to misunderstand the relationship between driver impairment and bodily concentrations of tetrahydrocannabinol (THC), the primary psychoactive constituent of cannabis.

Levels of THC in blood and oral fluid are poor indicators of impairment. A meta-analysis by McCartney et al. (2022) on THC concentrations in blood and oral fluid found that “THC-related biomarkers were not associated with impairment in regular cannabis users” and that “blood THC concentration was the poorest correlate of impairment demonstrating a ‘very weak’ relationship after both ingestion (R=-0.08) and inhalation (R=-0.10) of THC.” In other words, neither blood nor oral fluid testing is indicative of the  level of impairment to a meaningful degree. It is certainly not the strong relationship seen between blood alcohol levels and driver impairment (McCartney et al. 2022). The crime in question is supposed to be impaired driving, so why is a measurement that does not accurately reflect impairment being used?

Tetrahydrocannabinol also stays in the body well after impairment has ended. A systematic review of residual THC levels after use concluded that “Blood THC >2 ng/mL, and possibly even THC >5 ng/mL, does not necessarily represent recent use of cannabis in frequent cannabis users” and that some users had levels >2 ng/ml for over a week after use (Peng et al. 2020). For reference, the current legislation outlines a tolerance blood concentration of 1ng/ml and a ‘high risk’ concentration of 3ng/ml. Considering that almost all driving related impairment subsides after 7 hours of inhalation (McCartney et al. 2021), it seems that completely unimpaired drivers will still be charged with a crime - even without equipment malfunction.

Whilst we have primarily focused on THC here given cannabis is the most commonly used illicit drug in New Zealand (Ministry of Health 2023), similar issues arise for other drugs as well. A recent study by Heide et al. (2024) found no relationship between blood concentration levels of MDMA and driver impairment. Whilst this paper did find a relationship between blood cocaine concentration and driver impairment, they found that 46% of the cocaine positive drivers in the study were not clinically impaired. The lowest blood cocaine concentration in this study was 20ng/l, whilst the tolerance level of cocaine under our current legislation is just 5ng/l. Thus, this research suggests that almost half of the drivers studied were not impaired by the level of cocaine in their blood and yet, all of these people would have been penalized by the proposed drug detection protocol. A similar finding was identified with MDMA, with 62% of MDMA users in the study not being clinically impaired, despite having blood concentrations of MDMA that would be illegal under this legislation.

Furthermore, increased tolerance to drug effects in people who consume regularly, for medical reasons or otherwise, will lead to said consumers having higher concentrations of detectable compounds present within their body. Due to increased drug tolerance in these individuals, they are less likely to be impaired by these heightened concentrations and thus, are highly likely to be penalized despite not driving whilst impaired. In the case of opioid use, it has been shown that drivers who consume a steady and regular dose are not impaired (Wilhelmi and Cohen 2012). SSDP is concerned that if this evidence goes underappreciated, a large number of responsible drug consumers, who do not drive while impaired, will be unfairly impacted. People who use drugs regularly, people suffering from chronic pain, and those with substance use disorders will be particularly discriminated against.

Poor accuracy of the tests:

Whilst it is unclear which tests are proposed for use in New Zealand, devices used in Australia have been found to have false negative rates of 9% and 16%, and false positive rates of 5% and 10% (Australian Broadcasting Corporation 2019). The proposed bill does attempt to mitigate this by relying on at least two positive tests. This would slightly increase the number of false negatives, and would reduce the number of false positives to 5.5% and 0.01% respectively (New Zealand Attorney-General, 2024). Considering the proposed quota of ~50,000 drivers tested a year (Newstalk ZB 2023), this would amount to over 4,500 and 8,000 drivers with ‘impairing’ levels of drugs in their system not being stopped and would result in up to ~2,750 drivers being unreasonably detained and suspended from driving. SSDP believes that this level of inaccuracy is unacceptably high and a waste of resources.

Issues with the quota system:

Having a quota incentivises oral fluid testing even if it is not required. Much of the media attention and statements from politicians around this bill has referred to key benefits of this technology as it will enable more rapid testing of more people with less training required. SSDP is concerned that this type of testing will be used to push out the compulsory impairment test (CIT) currently in use, thus replacing a literal test for impairment with a test that has been shown by research to have little correlation with impairment for many drug types. The quota system is likely to further speed up this replacement of the CIT as it incentivises police officers to do an oral test rather than an impairment test (CIT).

This type of quota driven ‘proactive policing’ approach has been tried before and has been linked to far greater rates of racial and classist discrimination by police officers in Australia (Australian Broadcasting Corporation 2024). We know that Māori and Pasifika are disproportionately policed and prosecuted in New Zealand and this legislation is likely to exacerbate this.

Inconsistencies with the bill of rights:

The Attorney General has made clear in their report that this bill is “inconsistent with s 21 (right to be secure against unreasonable search and seizure) and s 22 (right not to be arbitrarily detained) and cannot be justified under s 5 of the Bill of Rights Act.” (New Zealand Attorney-General, 2024). It was concluded by the attorney general that there is a sufficient rationale for implementing these tests. We can all agree that measures to prevent impaired driving are important. However, the Attorney General also concluded that the proposed roadside testing was not adequate to justify the considerable intrusion on bodily privacy, the unreasonable seizure of tissue samples (and potentially a persons car keys), and the unreasonable detainment of innocent persons for up to a half hour or more. The current impairment test requires reasonable grounds for testing to occur thus keeping it in line with the New Zealand Bill of Rights Act.

Conclusion/recommendations:

SSDP has the following recommendations in regards to this bill:

1. The biggest flaw of this legislation is the lack of evidence base. The inaccuracy of the currently available testing technologies, the poor research linking drug concentrations and driver impairment, and the poor research linking roadside drug testing to reductions in road deaths, accidents, or injuries is a considerable issue. SSDP recommends that these gaps in understanding be closed before such a system is implemented, to determine if such a scheme will ultimately benefit public safety without increasing discrimination and harm. If the government is serious about implementing this system, significant research should be dedicated to solving these issues beforehand.

2. Currently there are no proposed guidelines on what dosages of different drugs may cause a driver to be impaired, or how much time should pass post-consumption before a driver is deemed “safe” to operate a vehicle. As previously mentioned, this is likely not possible because there is a lack of research on this topic. Blood concentrations mean very little to the average person. This needs to be converted into typical drug dosages. Before implementing any type of roadside testing, the government should determine clear dosages that are likely to impair a driver, followed by public awareness campaigns that enable people who use drugs to better understand when they are likely to be impaired. With alcohol, we know not to drive after having more than two standard drinks. Similar education campaigns should be pursued for drug driving. Greater availability of quantitative drug checking services would enable people who use drugs to better gauge their consumption.

3. Currently the high false positive rates of the tests as well as the fact that many unimpaired people may have blood concentrations above the stated limits will result in significant penalisation of people who use drugs, including those who consume for medical reasons. There should be a requirement to prove impairment of any person who is to be penalized under this legislation. Proof of drug presence does not prove that a person is impaired.

4. The proposed quota system incentivises excessive policing, is likely to exacerbate discriminatory policing practices, and is likely to incentivise a move away from the CIT to mostly oral fluid testing. Due to the points previously made, SSDP recommends not implementing quotas for roadside drug testing, and ensuring that CIT is still used alongside, or instead of, these tests. If the New Zealand police force believes that a true test for impairment is too burdensome on its officers, then they should invest in the development of more accurate, less burdensome impairment tests. Blood and oral fluid drug testing is not such a test.

5. The bill is currently inconsistent with the Bill of Rights Act due to the lack of requirement for reasonable suspicion that a person is impaired by drugs before undergoing a test. If roadside testing is to be implemented, it should not be allowed unless there are reasonable grounds to suspect a person of drug impaired driving.

If the government truly wishes to prevent drug impaired driving, they will invest in further research of drug-specific impairments that relate to driving performance, so that they may develop novel methods which can accurately identify drug impairment. Other methods that would aid in limiting drug impaired driving are greater public transport accessibility, particularly late at night, education campaigns, and measures to improve the quality of the drug supply (or greater accessibility to quantitative drug checking services) to ensure that people who use drugs are better able to dose appropriately if planning to drive later. Lowering speed limits, increasing road signage, and many other methods could be used to reduce traffic accidents more generally.

References:

Australian Broadcasting Corporation. (2019). Police roadside cannabis drug-testing devices questioned. ABC News. https://www.abc.net.au/news/2019-09-12/police-roadside-cannabis-drug-testing-devices-questioned/11502436

ABC News. (2024). How proactive policing quotas sent NSW police searches soaring. https://www.abc.net.au/news/2024-03-18/how-proactive-policing-quotas-sent-nsw-police-searches-soaring/103579210

Crossin, R., Cleland, L., Wilkins, C., Rychert, M., Adamson, S., Potiki, T., ... & Boden, J. (2023). The New Zealand drug harms ranking study: A multi-criteria decision analysis. Journal of Psychopharmacology, 37(9), 891-903.

Heide, G., Jamt, R. E. G., Fainberg-Sandbu, J., Øiestad, Å. M. L., & Høiseth, G. (2024). Driving under the influence of cocaine and MDMA: Relationship between blood concentrations and results from clinical test of impairment. Journal of analytical toxicology, 48(5), 380-387.

New Zealand Attorney-General. (2024). Report of the Attorney-General under the New Zealand Bill of Rights Act 1990 on the Land Transport (Drug Driving) Amendment Bill. Wellington, New Zealand: Published by Order of the House of Representatives. https://bills.parliament.nz/v/4/4a1add47-2008-4fa0-75b4-08dcaf6f1ee5

Newstalk ZB. (2023). Not buckling up could cost $450 as Government Policy Statement targets seatbelt use. https://www.newstalkzb.co.nz/news/national/not-buckling-up-could-cost-450-as-government-policy-statement-targets-seatbelt-use/

McCartney, D., Arkell, T. R., Irwin, C., & McGregor, I. S. (2021). Determining the magnitude and duration of acute Δ9-tetrahydrocannabinol (Δ9-THC)-induced driving and cognitive impairment: A systematic and meta-analytic review. Neuroscience & Biobehavioral Reviews, 126, 175-193.

McCartney, D., Arkell, T. R., Irwin, C., Kevin, R. C., & McGregor, I. S. (2022). Are blood and oral fluid Δ9-tetrahydrocannabinol (THC) and metabolite concentrations related to impairment? A meta-regression analysis. Neuroscience & Biobehavioral Reviews, 134, 104433.

Ministry of Health. 2023. Annual Data Explorer 2022/23: New Zealand Health Survey [Data File]. URL: https://minhealthnz.shinyapps.io/nz-health-survey-2022-23-annual-data-explorer/

Peng, Y. W., Desapriya, E., Chan, H., & Brubacher, J. R. (2020). Residual blood THC levels in frequent cannabis users after over four hours of abstinence: A systematic review. Drug and alcohol dependence, 216, 108177.

Wilhelmi, B. G., & Cohen, S. P. (2012). A framework for “driving under the influence of drugs” policy for the opioid using driver. Pain physician, 15(3S), ES215.