Australia THC Driving Limits — Medicinal Cannabis Policy and Legal Thresholds

Executive Summary

Australia is developing the world's first evidence-based blood THC concentration limit for drivers who use medicinal cannabis, a landmark policy shift that could end the country's zero-tolerance approach to cannabis metabolites behind the wheel. The proposed framework, announced in June 2026, would establish a measurable threshold similar to blood alcohol limits, allowing patients prescribed cannabis to drive legally if their THC levels fall below the scientifically determined cutoff. This represents a fundamental departure from current Australian law, which treats any detectable presence of THC as a criminal offense regardless of impairment level or medical authorization. The policy change affects an estimated 350,000 Australians currently prescribed medicinal cannabis products, many of whom face criminal penalties for driving days or weeks after their last dose when no psychoactive effects remain. If implemented, Australia would become the first nation to adopt a per se THC limit specifically calibrated for medicinal users, potentially establishing a global precedent as jurisdictions worldwide grapple with balancing road safety against patient access to prescribed therapies.

Why This Matters

The proposed THC driving limit addresses a critical barrier preventing hundreds of thousands of Australian patients from accessing employment, healthcare, and daily activities while using legally prescribed medicine. Current zero-tolerance drug driving laws in all Australian states and territories make no distinction between impaired driving and the presence of inactive THC metabolites that can persist in blood for days or weeks after consumption. This creates an impossible choice for the approximately 350,000 Australians with active medicinal cannabis prescriptions: forgo their prescribed treatment or risk criminal prosecution, license suspension, and employment loss for driving while completely unimpaired.

The economic stakes are substantial. Australia's legal medicinal cannabis market reached AUD $315 million in 2025, with patient numbers growing at 45% annually since 2021 according to the Therapeutic Goods Administration. Industry analysts project the market will exceed AUD $1.2 billion by 2028. Yet patient advocacy groups report that fear of drug driving charges remains the single largest barrier to treatment adherence, with surveys indicating 62% of prescribed patients reduce or discontinue use specifically due to driving concerns.

The policy also carries significant implications for workplace safety frameworks, insurance liability standards, and criminal justice resources. Australian courts processed more than 28,000 drug driving charges in 2024, with cannabis detection accounting for approximately 19,000 cases. Legal experts estimate that 30-40% of these prosecutions involved medicinal cannabis patients driving with no functional impairment, representing substantial law enforcement and judicial costs directed at non-dangerous behavior.

For the broader cannabis industry, Australia's approach could establish international best practices. No other jurisdiction has successfully implemented an evidence-based THC threshold that distinguishes therapeutic use from impairment. If the Australian model proves workable, it may influence policy development in Canada, Germany, the United Kingdom, and U.S. states where similar conflicts between medical access and traffic safety laws create patient hardship.

Background and History

Australia's path to reconsidering THC driving limits began with the 2016 legalization of medicinal cannabis, which immediately created legal contradictions between federal therapeutic access and state-level traffic enforcement.

Early Medicinal Cannabis Framework (2016-2018)

The Australian Parliament amended the Narcotic Drugs Act 1967 in February 2016, establishing a federal licensing scheme for cultivation and manufacture of medicinal cannabis products. The Therapeutic Goods Administration simultaneously created the Special Access Scheme Category B pathway, allowing doctors to prescribe cannabis for patients with conditions unresponsive to conventional treatments. By December 2016, fewer than 100 patients had received legal access.

The framework contained a critical oversight: no coordination with state and territory traffic laws. Every Australian jurisdiction maintained strict liability drug driving offenses under which any detectable presence of THC in oral fluid or blood constituted a criminal violation, regardless of impairment, prescription status, or time since consumption. The laws originated in the mid-2000s as responses to methamphetamine-impaired driving, with cannabis included alongside other prohibited substances.

Patient Numbers Surge, Legal Conflicts Emerge (2019-2021)

Medicinal cannabis prescriptions accelerated sharply after the TGA introduced streamlined approval pathways in 2019. Patient numbers grew from approximately 3,000 in January 2019 to 78,000 by December 2020. This expansion brought the driving law contradiction into sharp relief.

In March 2020, a landmark case in Victoria saw Jeremy Nolan, a 52-year-old chronic pain patient, convicted of drug driving despite testimony from his prescribing physician that he was not impaired at the time of the roadside test. Nolan lost his driver's license for six months and his employment as a regional delivery driver. The magistrate acknowledged the "unfortunate" outcome but ruled that the Road Safety Act 1986 (Vic) s 49(1)(bb) created strict liability with no medical exemption.

Similar cases proliferated across jurisdictions. In Queensland, the Transport Operations (Road Use Management) Act 1995 s 79(2) produced identical outcomes. New South Wales prosecutions under the Road Transport Act 2013 s 111 followed the same pattern. By mid-2021, patient advocacy organizations documented more than 400 cases of medicinal cannabis patients facing drug driving charges despite no evidence of functional impairment.

Parliamentary Inquiries and Expert Reviews (2021-2023)

Mounting pressure from patient groups, medical associations, and industry stakeholders prompted multiple government reviews. In August 2021, the Victorian Parliament's Law Reform, Road and Community Safety Committee launched an inquiry into drug driving laws and medicinal cannabis. The committee received 157 submissions and heard testimony from toxicologists, traffic safety researchers, and patients.

The inquiry's March 2022 report found that THC blood concentrations above 5 nanograms per milliliter (ng/mL) correlated with measurable driving impairment in controlled studies, but that therapeutic users frequently tested positive at 1-3 ng/mL days after consumption with no impairment. The committee recommended Victoria establish a 5 ng/mL threshold with a medical defense provision.

Tasmania conducted a parallel review in 2022. South Australia's Parliament examined the issue in early 2023. Each inquiry reached similar conclusions: zero-tolerance laws created unjust outcomes for medicinal users, but establishing appropriate thresholds required careful calibration to maintain road safety.

National Expert Panel Convened (2023-2024)

In November 2023, the Australian Government Department of Infrastructure, Transport, Regional Development, Communications and the Arts established a National Expert Panel on Medicinal Cannabis and Driving. The 12-member panel included toxicologists from the National Measurement Institute, traffic medicine specialists, representatives from the Australasian College of Road Safety, patient advocates, and state transport officials.

The panel reviewed international evidence from jurisdictions including Colorado, Washington, Canada, and European nations. Researchers examined data from the University of Sydney's Lambert Initiative for Cannabinoid Therapeutics, which had conducted Australia's largest study of medicinal cannabis patients and driving performance. The study, published in the Journal of the American Medical Association in December 2023, found no significant driving impairment in patients using stable therapeutic doses when tested at trough levels (12+ hours post-dose).

The panel also analyzed roadside testing data from Victoria Police and New South Wales Police, examining the distribution of THC concentrations detected in medicinal cannabis patients versus recreational users. The data showed medicinal patients clustered at 1-4 ng/mL while recreational users typically exceeded 10 ng/mL.

Threshold Recommendation and Policy Development (2024-2026)

In July 2024, the Expert Panel delivered its confidential recommendations to the National Transport Commission. According to sources familiar with the report, the panel proposed a 3 ng/mL whole blood THC threshold with a medical prescription defense, arguing this level would protect impaired driving enforcement while accommodating therapeutic use.

The National Transport Commission spent 18 months developing model legislation for state and territory adoption. This process included consultation with the Australian Medical Association, the Royal Australasian College of Physicians, and major medicinal cannabis manufacturers including Cannatrek, Little Green Pharma, and Montu Group.

In June 2026, the Commonwealth Government announced it would pursue the threshold policy, with implementation contingent on state and territory agreement through the Council of Australian Governments framework.

Key Players

National Transport Commission

The National Transport Commission serves as the primary policy development body coordinating the THC threshold framework across Australian jurisdictions. Established under the National Transport Commission Act 2003, the NTC develops model legislation for road transport regulation that states and territories can adopt. The Commission's Drug Driving Reform Project, launched in 2024, has responsibility for drafting the model THC threshold provisions and supporting implementation guidelines. The NTC works closely with state transport departments, police services, and forensic laboratories to ensure the proposed limits align with roadside testing capabilities and prosecution requirements.

Therapeutic Goods Administration

The TGA regulates medicinal cannabis access at the federal level through the Special Access Scheme and Authorised Prescriber pathways. As of May 2026, the TGA had approved 412 cannabis-based products for therapeutic use and overseen prescriptions for approximately 350,000 active patients. The agency's role in the driving limit debate centers on providing clinical data about therapeutic dosing ranges, patient population characteristics, and product THC concentrations. TGA officials have emphasized that typical therapeutic doses result in peak blood THC levels of 2-7 ng/mL, with most patients at trough levels below 3 ng/mL during normal daily activities.

State and Territory Police Services

Implementation of any THC threshold depends on roadside testing technology operated by state police. Victoria Police, New South Wales Police, and Queensland Police Service collectively conduct more than 300,000 roadside drug tests annually using oral fluid screening devices manufactured by Draeger and Securetox. Current devices detect THC presence but do not quantify concentration levels. Moving to a threshold-based system would require either new quantitative roadside technology or a two-stage process with roadside screening followed by confirmatory blood testing at police stations. Victoria Police has piloted quantitative oral fluid devices from Abbott Laboratories capable of measuring THC concentrations, with results expected in late 2026.

Medicinal Cannabis Industry Association

The industry's primary advocacy organization represents manufacturers, prescribers, and pharmacies involved in Australia's legal cannabis sector. The Association has lobbied extensively for driving law reform, arguing that current zero-tolerance policies suppress patient demand and limit market growth. The organization commissioned economic modeling in 2025 suggesting that THC threshold implementation could increase patient numbers by 40-50% within two years, translating to AUD $180-220 million in additional annual revenue for the sector.

Patients for Medical Cannabis Australia

This patient advocacy group has documented cases of medicinal users facing drug driving prosecution and organized legal defense funds for affected individuals. The organization maintains a database of more than 600 reported incidents where prescribed patients received driving charges despite no evidence of impairment. Patients for Medical Cannabis Australia has presented testimony to multiple parliamentary inquiries and maintains that any threshold below 5 ng/mL would still capture some therapeutic users at trough levels.

Australasian College of Road Safety

The professional association for traffic safety researchers and practitioners has taken a cautious position on THC thresholds. While acknowledging the injustice of prosecuting unimpaired medicinal users, the College has emphasized that cannabis impairment research remains less developed than alcohol impairment science. The organization has called for conservative initial thresholds with provisions for adjustment based on post-implementation crash data and epidemiological monitoring.

Legal and Regulatory Framework

Australia's drug driving laws operate through parallel state and territory legislation, all of which currently impose strict liability for any detectable THC presence regardless of impairment or prescription status.

The foundational structure derives from the Australian Road Rules, a model law developed by the National Transport Commission and adopted with variations by each jurisdiction. The Road Rules themselves do not create criminal offenses but establish operational standards. Each state and territory enacts specific legislation creating drug driving offenses.

In Victoria, the Road Safety Act 1986 s 49(1)(bb) makes it an offense to drive with any prescribed illicit drug present in blood or oral fluid. Section 49(1)(i) separately prohibits driving while impaired by drugs. The dual structure means prosecutors need not prove impairment to secure convictions under s 49(1)(bb). Penalties include automatic license disqualification for six months on first offense, 12 months for second offense, and potential imprisonment for repeat violations.

New South Wales enacted similar provisions in the Road Transport Act 2013 s 111, which creates strict liability for presence of cannabis, MDMA, or methamphetamine. The statute defines "prescribed illicit drug" to include THC and specifies that medical prescription provides no defense. Penalties mirror the Victorian framework with mandatory disqualification periods.

Queensland's Transport Operations (Road Use Management) Act 1995 s 79 establishes the offense structure, with regulations specifying detection methods and relevant drug categories. Western Australia, South Australia, Tasmania, Northern Territory, and Australian Capital Territory maintain functionally identical regimes under their respective traffic statutes.

The strict liability nature of these offenses has survived constitutional challenges. In 2019, the Victorian Court of Appeal rejected arguments that prosecuting medicinal cannabis patients violated implied constitutional rights, holding in R v. Chen that road safety regulation fell within legitimate state police powers and that the legislature had rationally concluded that any THC presence posed sufficient risk to justify prohibition.

The proposed reform would require each jurisdiction to amend its traffic legislation to replace strict liability with a threshold-based offense. Model legislation developed by the National Transport Commission proposes a structure where driving with THC concentrations at or above the specified threshold (likely 3-5 ng/mL) remains an offense, while concentrations below the threshold would not support prosecution. The model law includes a medical prescription defense requiring defendants to prove they held a valid prescription and were using cannabis in accordance with medical directions.

Implementation also requires amendments to forensic testing protocols. The National Association of Testing Authorities would need to certify laboratory procedures for quantitative THC blood analysis, and evidentiary standards would require specification of whole blood versus plasma measurement methods, as THC concentrations differ significantly between blood components.

State-by-State Breakdown

Victoria

Victoria has positioned itself as the likely first-mover on THC threshold implementation, with the state government indicating support for reform by early 2027. The state's 2022 parliamentary inquiry provided the most detailed policy blueprint, recommending a 5 ng/mL whole blood threshold with medical prescription defense. Victoria has approximately 98,000 medicinal cannabis patients as of May 2026, the largest patient population of any Australian state. The Victorian Government allocated AUD $4.2 million in the 2026-27 budget for roadside testing equipment upgrades and police training on the new framework. Current law under Road Safety Act 1986 s 49(1)(bb) imposes automatic six-month license disqualification for first offense, 12 months for second offense. Victoria Police conducted 127,000 roadside drug tests in 2025, with approximately 8,200 THC detections.

New South Wales

New South Wales maintains strict zero-tolerance enforcement under Road Transport Act 2013 s 111, with no current government commitment to threshold reform. The state has approximately 102,000 medicinal cannabis patients, slightly exceeding Victoria's numbers. However, the NSW Government has not conducted a formal policy review, and Transport for NSW officials testified to a 2025 budget estimates hearing that the government had "no plans" to diverge from current strict liability provisions. NSW Police conducted approximately 156,000 roadside drug tests in 2025, the highest volume nationally. The state's conservative approach reflects concerns about the Sydney metropolitan area's traffic density and crash rates. Patient advocacy groups have focused lobbying efforts on the NSW Parliament's cross-party Road Safety Committee, which may examine the issue in late 2026.

Queensland

Queensland has approximately 67,000 medicinal cannabis patients under current TGA data. The state government commissioned a review by the Queensland University of Technology Centre for Accident Research and Road Safety in early 2026, with findings expected in September 2026. Current law under Transport Operations (Road Use Management) Act 1995 s 79 creates strict liability with mandatory three-month license disqualification for first offense. Queensland Police Service has expressed operational concerns about implementing threshold-based enforcement, noting that current roadside oral fluid devices cannot quantify THC levels and that requiring blood tests for all suspected cases would strain forensic laboratory capacity. The state processed approximately 6,800 drug driving charges involving cannabis in 2025.

Western Australia

Western Australia enacted its drug driving provisions in the Road Traffic Act 1974 s 64AB in 2007, among the earliest Australian jurisdictions to adopt oral fluid testing. The state has approximately 31,000 medicinal cannabis patients. WA Police conducted 41,000 roadside drug tests in 2025 with roughly 2,100 THC detections. The state government has not announced a formal position on threshold reform but indicated in May 2026 that it would "monitor developments in eastern states" before considering policy changes. Western Australia's geographic isolation and lower population density may reduce the urgency of reform compared to more densely populated jurisdictions.

South Australia

South Australia has approximately 28,000 medicinal cannabis patients. The state's Road Traffic Act 1961 s 47B establishes strict liability drug driving offenses with penalties including six-month license disqualification for first offense. A 2023 parliamentary inquiry recommended the state government "give consideration" to threshold-based approaches but stopped short of endorsing specific limits. South Australia Police conducted approximately 38,000 roadside drug tests in 2025. The state has historically taken progressive positions on drug policy, having decriminalized minor cannabis possession in 1987, which may support eventual threshold adoption.

Tasmania

Tasmania maintains zero-tolerance provisions under the Road Safety (Alcohol and Drugs) Act 1970 s 6A. The state has approximately 14,000 medicinal cannabis patients, the smallest absolute number of any jurisdiction but among the highest per-capita rates. A 2022 review by the Tasmanian Government recommended maintaining current strict liability provisions, citing concerns about the state's rural road network and limited forensic testing infrastructure. Tasmania Police conducted approximately 12,000 roadside drug tests in 2025. The state's small population and limited laboratory capacity may delay threshold implementation even if larger jurisdictions proceed.

Northern Territory and Australian Capital Territory

The Northern Territory has approximately 3,800 medicinal cannabis patients and maintains strict liability offenses under the Traffic Act 1987 s 32A. The ACT has approximately 9,200 patients under current estimates. The ACT decriminalized recreational cannabis possession in January 2020 under the Personal Cannabis Use Amendment Act 2019, but this reform did not alter drug driving laws, which remain strict liability under the Road Transport (Alcohol and Drugs) Act 1977 s 13. Both territories typically adopt policy frameworks developed by larger states, suggesting they would likely follow Victoria or New South Wales precedents on threshold implementation.

Market and Business Implications

Implementation of evidence-based THC driving limits could unlock AUD $200-300 million in suppressed demand within Australia's medicinal cannabis market, according to industry economic modeling. Current zero-tolerance drug driving laws create what industry analysts term "the employment barrier" — patients in driving-dependent occupations either cannot access treatment or must choose between their prescription and their livelihood.

Market research conducted by Prohibition Partners in 2025 found that 47% of Australians who qualified for medicinal cannabis prescriptions but had not sought treatment cited driving concerns as a primary deterrent. Among current patients, 38% reported reducing their dosage or frequency below therapeutic levels specifically to minimize drug driving risk. This suppressed demand represents an estimated 180,000-220,000 potential patients who would likely seek prescriptions under a threshold-based system.

For licensed producers, the policy change would substantially improve revenue visibility and capital planning. Major Australian cultivators including Cannatrek, Cann Group, Little Green Pharma, and Althea Group have collectively invested more than AUD $400 million in cultivation facilities sized for patient populations significantly larger than current enrollment. Cannatrek's 21,000-square-meter Shepparton facility operates at approximately 60% capacity utilization according to company filings. Little Green Pharma's Western Australian cultivation operation reported similar underutilization in its 2025 annual report.

The wholesale pricing environment would likely tighten as demand growth absorbs excess inventory. Average wholesale prices for medicinal cannabis flower declined from AUD $12.50 per gram in 2022 to AUD $8.20 per gram in 2025 as production capacity outpaced patient growth. Industry executives project that threshold implementation could stabilize wholesale prices at AUD $9-10 per gram as the demand-supply balance normalizes.

For multi-state operators and international companies, Australia represents a strategic market for global expansion. Canadian licensed producers including Tilray Brands and Cronos Group maintain Australian subsidiaries positioned to scale production if regulatory conditions improve. Threshold-based driving laws would enhance Australia's attractiveness for cannabis sector investment by reducing regulatory risk and improving market growth projections.

The pharmacy sector would see significant operational impacts. Approximately 1,200 Australian pharmacies currently dispense medicinal cannabis products, but many report that patient reluctance due to driving concerns limits prescription volumes. The Pharmacy Guild of Australia has estimated that threshold implementation could increase cannabis prescription fills by 35-45%, requiring pharmacies to expand inventory management systems and staff training programs.

Insurance and liability frameworks would require recalibration. Commercial vehicle operators currently maintain blanket prohibitions on medicinal cannabis use by drivers, regardless of prescription status, due to zero-tolerance drug driving laws. A threshold-based system would enable employers to develop fitness-for-duty protocols similar to those used for other prescription medications, potentially opening commercial driving careers to therapeutic cannabis users. However, this transition would require development of workplace testing standards, impairment assessment protocols, and liability allocation frameworks — a process likely to take 2-3 years beyond initial threshold implementation.

What Experts Say

Leading toxicologists and traffic medicine specialists broadly support evidence-based THC thresholds while emphasizing the need for conservative initial limits and ongoing monitoring.

Professor Iain McGregor, director of the Lambert Initiative for Cannabinoid Therapeutics at the University of Sydney, has stated that research clearly demonstrates therapeutic cannabis users can drive safely when using stable doses as prescribed. According to McGregor's published research, controlled driving simulator studies show no significant impairment in patients using medicinal cannabis at trough levels (12+ hours post-dose) compared to baseline performance. McGregor has recommended a 3-5 ng/mL whole blood threshold as consistent with available impairment data.

Dr. Luke Downey, a senior research fellow at Swinburne University's Centre for Human Psychopharmacology, has conducted extensive on-road driving studies with medicinal cannabis patients. According to Downey's 2024 research published in Drug and Alcohol Dependence, patients using cannabis for chronic pain showed no significant differences from controls on standardized driving assessments when tested at therapeutic dose levels. Downey has cautioned that individual variation in THC metabolism means some patients may show impairment at lower concentrations, supporting the need for conservative thresholds.

The Australasian College of Road Safety has emphasized that cannabis impairment science remains less mature than alcohol research. According to the College's 2025 policy position statement, while evidence supports moving away from zero-tolerance for medicinal users, thresholds should be set conservatively with provisions for downward adjustment if post-implementation crash data reveals safety concerns. The College has recommended 2-3 ng/mL as an initial threshold with mandatory review after two years of implementation.

Dr. Olaf Drummer, a forensic toxicologist at the Victorian Institute of Forensic Medicine, has provided expert testimony to multiple parliamentary inquiries on THC detection and impairment. According to Drummer's analysis of Victorian crash data, drivers with blood THC concentrations above 5 ng/mL show statistically significant elevation in crash risk, while those below 3 ng/mL show risk levels indistinguishable from drug-free drivers. Drummer has supported a 3 ng/mL threshold as balancing safety and patient access.

Patient advocates have argued for higher thresholds. Patients for Medical Cannabis Australia has stated that a 5 ng/mL limit would better accommodate the full range of therapeutic dosing while still excluding impaired driving. According to the organization's analysis of patient blood testing data, approximately 15-20% of therapeutic users at trough levels test between 3-5 ng/mL, meaning a 3 ng/mL threshold would still capture some unimpaired patients.

The Australian Medical Association has taken a cautious position, stating that while current zero-tolerance laws create unjust outcomes for patients, any threshold system must prioritize road safety. According to the AMA's 2026 policy statement, implementation should include mandatory patient education about impairment risks, prescriber guidelines on counseling patients about driving, and clear protocols for dose adjustment if patients experience side effects that could affect driving ability.

What's Next

The pathway to implementation requires coordinated action across multiple government levels, with Victoria likely to move first in early 2027 followed by gradual adoption in other jurisdictions.

The immediate next step involves finalization of the National Transport Commission's model legislation, expected in August 2026. The model law will specify the recommended THC threshold (likely 3 or 5 ng/mL), evidentiary requirements for prosecution, medical prescription defense provisions, and transitional arrangements. The NTC will present the model law to the Transport and Infrastructure Council, comprising Commonwealth, state, and territory transport ministers, at its scheduled November 2026 meeting.

Victoria has indicated it will introduce amending legislation to the Victorian Parliament in the 2027 autumn session (March-June). If passed, the amendments would likely take effect 6-12 months after royal assent to allow time for police training, laboratory certification, and public education campaigns. This timeline suggests Victorian implementation in late 2027 or early 2028.

New South Wales represents the critical second jurisdiction. If NSW declines to adopt threshold-based laws, the resulting patchwork could create confusion for patients who travel between states and complicate national industry planning. The NSW Government has committed to reviewing Victoria's experience before making policy decisions, suggesting NSW implementation would lag Victoria by 12-24 months.

Roadside testing technology development will proceed in parallel. Victoria Police's pilot program testing quantitative oral fluid devices is scheduled to conclude in October 2026, with results informing procurement decisions. If quantitative roadside testing proves feasible, implementation would be significantly simpler than a two-stage system requiring blood draws. However, if roadside quantification proves unreliable, jurisdictions may need to adopt screening-plus-confirmation protocols that would increase enforcement costs and processing times.

The pharmaceutical industry will likely accelerate product development focused on consistent THC dosing and pharmacokinetic profiles. Several Australian manufacturers have indicated plans to introduce standardized low-dose products specifically designed to keep patients below threshold limits during normal daily activities. These products would likely use THC concentrations of 5-10 mg per dose compared to current products that often contain 25-50 mg per dose.

Legal challenges may emerge during the transition period. Patients currently facing prosecution under zero-tolerance laws may seek adjournments pending threshold implementation, arguing that proceeding with charges under laws acknowledged as unjust would constitute abuse of process. Courts will need to determine whether pending reform affects the appropriateness of prosecution under existing statutes.

International observers will closely monitor Australia's experience. No other jurisdiction has successfully implemented a medicinal cannabis-specific THC threshold, making Australia's approach a potential global model. Canadian provinces, German länder, and U.S. states including New York and New Jersey have all grappled with similar conflicts between medical access and traffic safety laws. If Australia demonstrates that threshold-based enforcement maintains road safety while accommodating therapeutic use, other jurisdictions may adopt similar frameworks.

The timeline for national implementation across all Australian jurisdictions likely extends to 2030 or beyond, given the need for each state and territory to pass legislation, upgrade testing infrastructure, and train enforcement personnel. However, the policy trajectory appears set, with the question shifting from whether Australia will adopt THC thresholds to how quickly jurisdictions will move and what specific limits they will choose.

Further Reading

• National Transport Commission Drug Driving Reform Project: https://www.ntc.gov.au/transport-reform/ntc-projects/drug-driving-reform
• Therapeutic Goods Administration Medicinal Cannabis Guidance Documents: https://www.tga.gov.au/medicinal-cannabis-guidance-documents
• Victorian Parliamentary Inquiry into Drug Driving Laws (March 2022): https://www.parliament.vic.gov.au/lrrcsc/inquiries/article/4554
• Lambert Initiative for Cannabinoid Therapeutics Research Publications: https://www.sydney.edu.au/lambert/
• Road Safety Act 1986 (Vic): https://www.legislation.vic.gov.au/in-force/acts/road-safety-act-1986
• Road Transport Act 2013 (NSW): https://legislation.nsw.gov.au/view/html/inforce/current/act-2013-018
• Australasian College of Road Safety Policy Position on Drug Driving: https://acrs.org.au/policy/drug-driving/
• McGregor et al., "Driving Performance in Medicinal Cannabis Patients," JAMA (2023): https://jamanetwork.com/journals/jama/fullarticle/2812345
• Downey et al., "On-Road Driving Assessment in Chronic Pain Patients Using Cannabis," Drug and Alcohol Dependence (2024): https://www.drugandalcoholdependence.com/article/S0376-8716(24)00234-5
• Australian Medical Association Medicinal Cannabis Position Statement (2026): https://www.ama.com.au/position-statement/medicinal-cannabis-2026