People Against Drink/Drug Driving

A randomized, placebo-controlled, double-blind, pilot study of cannabis-related driving impairment assessed by driving simulator and self-report

Abstract

Aims: In the context of increasing cannabis use, understanding how cannabis affects specific driving behaviors is crucial in mitigating risks and ensuring road safety.

Design and setting: The current study included 38 adults aged 18–40 years, administered a single 0.5 g acute dose of vaporized cannabis (5.9% Tetrahydrocannabinol (THC), 13% THC or placebo) in a randomized, within-subject, double-blind, counterbalanced design. Throughout each of the three, 8-h assessment days, at 4 time points, participants underwent simulated driving tests, including lane-keeping, car following, and overtaking tasks, capturing 19 behavioral metrics. An SPSS linear mixed model assessed the main effects of dose, time, and dose × time.

Findings: During lane-keeping, participants exhibited reduced steering reversal rates up to 5.5 h following 13% THC and 3.5 h for 5.9%. For car following, participants showed reduced pedal peak-to-peak deviation and reversal rates, persisting for 1–3 h post-dose (only at 13% THC). During overtaking, following 13% THC, subjects demonstrated a shorter median gap to passed cars, lower time-to-potential collision, and more time in the oncoming lane. Drug effects on driving metrics improved gradually, to varying degrees over time. Approximately 66% of participants reported willingness to drive, despite subjective awareness of being impaired and objectively worse driving performance.

Conclusions: Our study reveals for the first time long-lasting cannabis-induced impairments across multiple driving behaviors, that extend beyond the typical 3-h window explored in most previous research. The observed discrepancy between participants’ willingness to drive and their actual impairment highlights an important public safety concern. In addition, the lack of correlation between cannabinoid metabolite concentrations and driving performance challenges the reliability of blood THC levels as impairment indicators, emphasizing the need for a multifaceted approach to assessing cannabis-impaired driving risk. (Source: Journal of Psychopharmacology)

Also see

• Effects of cannabis on visual function and self-perceived visual quality
• Cannabis (THC) messes with your Executive Functions – Can disrupt and impede good decision making and add to dysregulation
• Cannabis and Driving: Victorian Law Change for ‘Medicinal’ Cannabis Users – But is Road Safety Seriously Compromised?
• ‘Medicinal’ Cannabis & Driving – Is it an Issue? (DRR)

The system uses a saliva collection device to test impaired drivers for marijuana use as well as other drugs.

Over the last year, a group of officers with the Minnesota State Patrol carried a new piece of equipment in their squad cars. It looked like a Keurig machine, only this device doesn't make coffee; It analyzes saliva for THC — the chemical in marijuana that makes people high.

The machines were part of a pilot program that ended earlier this year, and the state patrol is preparing its results for state lawmakers. Minnesota is one of several states where police have tried this tool. They're doing so in response to changing behaviors: Most Americans now live in a state where marijuana is legal, more people are using it, and millions are doing so before driving.

Every state has a law that prohibits driving under the influence of drugs in some way, whether it be setting a permissible limit for legal drugs or not allowing any amount, but marijuana is difficult to regulate, and states are grappling with how to prevent people from driving under the influence.

"Essentially we've let the horse out of the barn," says Pam Shadel Fischer, senior director of external engagement with the Governors Highway Safety Association. "We need to make sure that we have things in place to protect others in the event that someone chooses to consume cannabis and get behind the wheel and be impaired."

Studies show THC can impair driving. It slows down driving speeds and reaction times and makes people swerve. Yet that varies widely by a person's tolerance to the drug, and the data is unclear on how big a problem driving while high actually is. In Colorado, for instance, fatal car crashes where a driver had THC in their blood went up after legalization. But it's difficult to determine whether a person was actively high at the time they crashed.

"When it comes to alcohol, the breath alcohol level is correlated very strongly with your blood alcohol level, which is correlated very strongly with your brain alcohol level," says Cinnamon Bidwell, an associate professor of psychology and neuroscience at the University of Colorado Boulder.

In other words, an alcohol breathalyzer is a good stand-in for how drunk and impaired a person is, but THC can stay in a person's system for hours, or even days, after they are no longer high.

"Can we detect THC accurately and reliably? The answer is yes. We can detect it in saliva. We can detect it in blood. We're working on reliable ways to detect it in breath," Bidwell says. "But what does that mean? And is there a level that means somebody recently used or that somebody is actively impaired? The data aren't there yet."

Without that, she says states risk over-punishing people who do use but don't drive while high.

Researchers, private companies and state governments are racing to find a tool that detects marijuana impairment with the ease and reliability of the alcohol breathalyzer.

In addition to Minnesota, officers in Alabama, Indiana, Michigan, Colorado and Wisconsin use or have piloted saliva tests. In Missouri, police have tested goggles that measure a driver's pupil size and movement. In Colorado, Bidwell is part of a team of researchers studying THC breathalyzers. In Vermont and Illinois, researchers have developed apps that could test a person's cognitive abilities roadside.

"We're all circling around the same question, which is, did you use recently?" says Ashley Brooks-Russell, an associate professor at the Colorado School of Public Health. "If someone's done something to cause a crash or be pulled over for a DUI, we want to know, are they impaired?"

Col. Matthew Packard, chief of the Colorado State Patrol, says with or without a test to back officers up, it's crucial to teach them what to look for. A test, he says, is just another tool.

"All that is, is confirming or supporting what you saw on the roadside," he says. "To use an ice cream analogy, the test is kind of like the cherry on the top, but ice cream is still great even if it doesn't have whipped cream and cherry." (for complete article  NPR)

Also see Cannabis and Driving: Victorian Law Change for 'Medicinal' Cannabis Users – But is Road Safety Seriously Compromised? - WRD News

Cannabis & Driving – Whilst old school sobriety tests will confirm intoxication in most instances, the 'lollipop – lick sticks’ ensures the so called 'seasoned' users and those who call their intoxicating substance ‘medicinal’ are also taken off the road. No one should drive any vehicle intoxicated - ever.

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Also see

1. Rising Need for Roadside Drug Testing
2. Cannabis and Driving: Victorian Law Change for ‘Medicinal’ Cannabis Users – But is Road Safety Seriously Compromised?

The rising prevalence of cannabis use, fuelled by its legalisation in many areas, is creating a significant road safety crisis. While society has long recognised the dangers of drink-driving, the risks associated with cannabis-impaired driving are not as widely understood, leaving communities vulnerable to preventable tragedies on the road.

The Challenges of Detecting Cannabis-Impaired Driving

One of the most pressing issues in addressing cannabis-impaired driving is the lack of reliable testing methods. Unlike alcohol, where blood-alcohol concentration levels are a proven indicator of impairment, there is no universally accepted standard to measure how recent cannabis use affects driving ability.

Existing blood tests can detect THC, the psychoactive compound in marijuana, but they fail to determine when it was consumed. THC lingers in the bloodstream long after its intoxicating effects have worn off, making current tests inaccurate for determining impairment. This gap gives cannabis-impaired drivers an unjust opportunity to escape accountability.

Additionally, portable devices capable of detecting cannabis use, akin to alcohol breathalysers, are still in development. Without such tools, law enforcement is left with limited means to identify cannabis-impaired drivers, exposing all road users to heightened risks.

Confusion in Cannabis Driving Laws

The legal frameworks surrounding cannabis and driving vary widely across regions, further complicating enforcement. Some states have adopted “zero-tolerance” policies, while others have implemented limits for THC levels in the bloodstream. However, these limits are not grounded in a clear understanding of how cannabis affects impairment, leaving them inadequate for ensuring safety.

Unlike alcohol, which universally impairs reflexes and judgement, the effects of cannabis differ depending on how it is consumed. Smoked cannabis takes effect quickly but wears off rapidly, while edibles produce longer-lasting but delayed effects. Compounding this is the tolerance developed by frequent users, which can mask conventional signs of impairment yet still put them at risk behind the wheel.

This inconsistency and lack of clarity leave drivers uncertain and underinformed, often resulting in dangerous behaviour on the road.

How Cannabis Use Impacts Driving Ability

Cannabis is known to adversely affect a driver’s ability to react to obstacles, judge distance, and make safe decisions. These impairments may not always manifest in the aggressive behaviour typically associated with drink-driving but can be equally dangerous. For example, cannabis users tend to drive slower, which some might interpret as caution. However, this perceived caution often disguises their impaired reflexes and focus.

Mounting evidence highlights the perils created by cannabis-impaired drivers. Surveys indicate a growing number of users admitting to driving after consuming marijuana, with many falsely believing that the drug either has no impact or even improves their driving performance. This misconception only amplifies the risks on our roads.

The Hidden Cost of Poor Enforcement

The rise in tragic cannabis-related accidents underscores the consequences of inconsistent laws and inadequate enforcement tools. Families who have lost loved ones in crashes involving marijuana-impaired drivers often find themselves grappling with injustice, as current legal frameworks fail to hold culprits fully accountable.

For instance, THC levels in blood samples taken after accidents cannot pinpoint if a driver was impaired at the time of the crash. This compounding issue means culpable drivers frequently evade responsibility, while victims’ families and communities bear the heart-wrenching fallout. Weak sentencing and blurred legal standards have fuelled a sense of public frustration and mistrust, underscoring the urgent need for reform.

Why Stronger Policies Are Vital

The devastating impact of cannabis-impaired driving highlights the need for stronger, clearer policies to protect road users and save lives. Legislative efforts focusing on accommodating cannabis use fail to address its inherent dangers, prioritising personal freedoms over societal safety. Without decisive action, the number of lives lost to cannabis-related accidents will only continue to rise.

Public education also plays a critical role in challenging misconceptions about cannabis and driving. It is essential to dismantle the myth of “safe” drug use behind the wheel and remind individuals that choosing to drive while impaired by any substance puts countless innocent lives at risk.

Keeping Safety as the Top Priority

Drug use and driving simply do not mix, yet the growing normalisation of cannabis is creating a dangerous illusion of safety on the roads. It is imperative that public safety takes precedence over the normalisation or commercialisation of substances like marijuana. By advocating zero tolerance for impairment on the roads, we can chart a course towards safer streets, better accountability, and a stronger commitment to protecting lives.

The message is simple yet critical—there is no safe way to drive under the influence of cannabis or any other substance. It’s time for society to unite in prioritising the safety of our roads for everyone. (WRD News)

Also see Cannabis and Driving: Victorian Law Change for ‘Medicinal’ Cannabis Users – But is Road Safety Seriously Compromised?

Rideshare service DiDi has launched a new tow truck initiative that’s aimed at discouraging drunk driving.

Melbourne residents can take part in the trial by ordering a tow truck to pick them up from the pub. The truck will pick up not just the driver but the car as well and then drop them off at a desired location.

The system will be available at no additional cost over the holiday season.

(P.A.D.D Comment: Whilst we laud all initiatives to keep drink and drug drivers off our roads, the downside of this initiative is that (as with most Harm Reduction only gimmicks) it can lend itself to a passive encouragement of not only drinking, but to excess. To marginally improve this ‘vehicle’ for better community health and safety, ‘Sober Thinking kit’ could be given to each user of the service, encouraging them to investigate, healthier and safer options all-round.) (

Source: Sky News