Over 40% of Deceased Drivers in Vehicle Crashes Test Positive for Thc: Study
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A recent study shook things up by revealing that over 40% of deceased drivers in vehicle crashes tested positive for THC, sparking a lively debate about the implications. Some commenters pointed out that correlation doesn't necessarily mean causation, with one suggesting that the "new recruits" who use cannabis because it's legal might also be more reckless drivers. Others questioned the assumption that seeing people vaping or smoking at stoplights means they're using cannabis, and highlighted the need to consider the context of THC use in the general population. The discussion also took a critical turn, with some commenters poking holes in the study's methodology and pointing out that fault wasn't evaluated, leaving many to wonder what's really driving the stats.
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One possible reason: the “new recruit” people who are now willing to use cannabis BECAUSE it is legal are also rule-following by being willing to stay off the road after using it. Perfectly plausible to me.
No it wouldn't.
People make those excuses because it's weed, but you would have never posted that on an article about alcohol.
(Not that it really matters since I don't buy for a second that anywhere near 40% of people/people-driving are high at any given time. I also don't put much faith in numbers in the abstract of a a yet-to-be-published study...)
THC in the blood doesn’t mean actively high for habitual users, which would be most users if THC consumption is high. It means recent use, but not clear impairment.
And the study doesn't seem to differentiate between the different types of THC either, some of which are not psychoactive at all and which people use to relieve pain and anxiety. There's quite a lot of people using non-psychoactive THC which wouldn't impair driving.
It doesn't say anything about the distribution, only that the "average" (presumably, the arithmetic mean, a measure particularly sensitive to distortion by outliers) was at a particularly high level.
Can you explain what you mean by this?
If 40% of the whole population has THC in them, we'd need a control population (maybe from earlier when thc was less prominent) to see if per capita deaths has meaningfully increased. I'd do the same study, tangentially, for tech workers to see if productivity has changed when controlling for other variables.
That would be true if you looked at a variable which is not influenced by driving, like the percentage that wear red jumpers, but one would hope that not everyone is reckless enough to be highly intoxicated and drive.
When we talk about alcohol, we explicitly separate presence from impairment using blood alcohol concentration. We set legal thresholds because studies show a sharp increase in crash risk above those levels, relative to sober drivers. If alcohol were evaluated by merely asking "was alcohol present?" we would massively overestimate its causal role the same way THC is being overestimated here.
The problem with THC data is not that baseline comparisons are illegitimate; it's that we lack an agreed-upon, time-linked impairment metric comparable to BAC. THC metabolites persist long after intoxication, so presence alone is a weak proxy for risk.
So applying baseline controls to THC is not "apologism", it's applying the same evidentiary standards we already demand for alcohol, so the opposite of what you said.
This is literally how safe legal limits were derived.
Why did you automatically assume the point of bias?
A similar result about alcohol would be the (hypothetical) statement that the rate of drunk drivers in fatal accidents was constant before and after the enactment of Prohibition.
I do agree that the fact that fatal THC% stays constant before and after legalization is a surprise.
Well of course not, as the two drugs have completely different intoxication side effects.
If we are at 40% of the population being high at any given moment I think we are having extremely serious societal problems around mental health. Occasional use is not a big deal IMHO, but if a person is spending 40% of waking hours impaired that person has some serious unmet psychological needs.
I'm arguing that if the population data looks anything like the autopsy data, it would imply a massive epidemic of THC overuse.
Not really, due to THC content in the body not being a reliable indicator of impairment or even time since use.
If BAC were more like THC levels, I suspect the data would show 40% or more of the population has consumed alcohol - or, in your words, is drunk "at any given moment"
Having said that, I think that effect explains only part of the 40%, but can't explain all of it.
That said, almost everyone I know that consumes THC has no qualms driving while doing it, and many of them also at work. It's a huge peeve of mine.
I wonder how many of these people were under the influence of alcohol and other substances.
The effects of alcohol on reaction time, coordination, and impulsivity/risk taking are huge, same with benzodiazepines.
The effects of THC aren’t even remotely similar to a regular user. I notice very little difference between driving sober and driving under the influence of THC.
I’ve been high enough on THC before when I had a low tolerance and was high enough where I knew not to drive.
That said, I don't do either. I also wouldn't take any amount of weed while working, but I'd feel comfortable having a beer during lunch if appropriate (work lunch/celebrate, e.g.).
Its not a sample, it is the whole universe of analysis. (If you treat it as a sample of, say, US drivers killed in accidents in the same period, then errors due to sample size are probably the least of its problems.)
The article says the research was "focusing on 246 deceased drivers who were tested for THC", and that the test usually happens when autopsies are performed. It doesn't say if autopsies are performed for all driver deaths, and it also doesn't say what exactly is "usually".
If (for example) autopsy only happens when the driver is suspected of drug use, then there's a clear selection bias.
Note that this doesn't mean the study is useless: they were able to see that legalization of cannabis didn't have impact on recreational use.
> In a review of 246 deceased drivers, 41.9% tested positive for active THC in their blood, with an average level of 30.7 ng/mL — far exceeding most state impairment limits.
Since COVID in CA, it feels like driving has become far more dangerous with much more lawlessness regarding excessive speeding and running red lights, going into the left lane to turn right in front of stopped cars, all sorts of weird things. But I can't tell if my anecdotes are significant. It seems that Ohio's impaired drivers have been consistent through the past six years though.
NYC has had the same effect since COVID, and over the last year or two it's gotten to the point where every single light at every busy intersection in Manhattan you get 2-3 cars speeding through the red light right after it turns. I bike ride a lot so I'm looking around at drivers a lot, and for the most part the crazy drivers seem to be private citizens in personal cars, not Uber or commercial/industrial drivers.
To the OP, I'm not sure I buy into it being tied to THC which seems to be the implication. Canada isn't seeing this trend, afaik.
But the data here also show that it's a consistent level before and after legalization of cannabis in Ohio. So legalization of cannabis in Ohio did not cause a big increase in impairment-levels of THC in those who died in traffic.
They do not, though, give an owl's hoot about yielding to straight traffic when turning. I suspect NY drivers are on a big group chat encouraging each other to cut off cyclists and pedestrians, by turning into their lane whenever they see one, and promptly parking there for an hour.
And there's the "squeeze", and "crowding the box". Almost like no car here is truly allowed to ever really stop so they're always gently rolling, just a little, juuuuust a little, just, maybe, I know it's red but maybe just a lil squeeze into the intersection, maybe, squeeze, ...
I don't know how to explain it but if you've been here you'll recognize it I'm sure.
Very frequently when there is a newsmaking incident in which a driver runs people over in some egregious fashion, it turns out that they got dozens of speed camera tickets per year. We know who these people are, we just don’t seem to have any motivation to actually do anything about it.
The city has published research on this, showing drivers who get 30+ speed camera tickets in a year are 50x as likely to be involved in crashes with serious injuries or death, but efforts to actually do something about their behavior are consistently stalled or watered down. Other research points to various causes, including backed up courts and decreased enforcement generally.
https://www.nyc.gov/html/dot/html/pr2025/nyc-dot-advocate-fo...
https://www.nyc.gov/html/dot/downloads/pdf/nyc-driver-behavi...
Cars are a weird sort of thing, where they both are the justification for a surveillance state and lots of monitoring, but we also have extremely lenient penalties. It's difficult for me to understand how the US arrived at our current set of laws.
Maybe that shouldn't be the only alternative in our society
Start punishing these people severely so that they might serve as an example to the rest
AFAIK, all evidence says that people don't consider consequences. If they did, they wouldn't be behaving like that in the first place. Punitive punishment feels much much better for people who have a specific set of values.
Remember from recent history these people that had 34 arrests or 73 arrests and they're out murdering people?
Now I'm not advocating for the second option there. Just something in between. (obviously a lot farther away than the second option).
Driving with license revoked or suspended was a serious charge and resulted in impound of vehicle and mandatory jail time. Repeat offenders would have their vehicles seized.
DUI laws similarly brutal. 2nd time offenders faced potentially life-altering charges and penalties. Get into an accident with injury to another person while DUI? Huge jail time. Felony DUI results in permanent loss of driving privileges.
Speeding 20 over the limit? Enjoy your reckless driving charge which is as serious a dui charge.
I read that getting a license back after a 2nd dui carries and average cost of $50k. Getting 2 dui's within 10 years automatically bumped 2nd dui to felony....no more driving for you.
Lax driving laws and penalties do nothing more than get a lot of people killed.
We're talking about NYC, they'll be fine without cars.
The modern world is so cat centric people would rather drive without a license than accept to live without a car. And until you can reliably catch and jail license-less drivers, the bet is worth it for them.
I previously lived in a country where the cops set up random roadblocks to check everyone's license & registration and look for signs of intoxication. When there's a real risk of waking up in a jail cell you're less likely to order that third beer. But in the US when renewing my tabs I feel like the joke's on me because half the cars here seem to have expired tabs or illegal plates and nobody ever checks.
1% is actually negligible, and would not have a deterrent effect. In fact I wouldn't even be surprised if the effective prosecution rate was somewhat higher than this already.
> I previously lived in a country where the cops set up random roadblocks to check everyone's license & registration and look for signs of intoxication.
I live in a country (France) where this is still the case, and where driving crimes are the second source of jail time after drug trafficking, yet alcohol is still the #1 cause of death on the road, and an estimate 2% of people drive without a license after having lost it (and are responsible for ~5% of accidents).
[0] https://en.wikipedia.org/wiki/List_of_countries_by_traffic-r...
Driving while intoxicated is not a crime of desperation. Even celebrities are often caught for DUI despite being able to afford a full-time limo driver.
Most people who drive intoxicated have jobs and reputations they'd prefer to keep, and families at home they would rather not be separated from or have to explain an arrest to.
And to be clear, we can't solve all the problems with a single measure. I'd like to see not just better law enforcement, but also a social safety net that ensures nobody is ever starving or homeless.
But if you're going to bring that up anyway, how are people supposed to get their car home from the bar in a place where the government hates public transport?
How did these people lose their license in the first place? The most common reason is DUIs. Followed by multiple instances of reckless driving. People are less likely to lose their license to begin with if they know there will be real consequences.
And there's a large enough population for whom driving without a license is not a crime of desperation. In many places there _is_ a public transport alternative (even if its slow and crappy). I used to give a lift every day to a colleague who had lost his license. I enjoyed the company and he paid for my gas. Many people can make an arrangement like this.
> But if you're going to bring that up anyway, how are people supposed to get their car home from the bar in a place where the government hates public transport?
Having been in this position many times: take an Uber, then Uber back to get your car the next day and plan better (or don't drink) next time.
If only
To me the answer is quite simple for any of these. Treat repeated small infractions like bigger and bigger infractions. E.g. double the cost every iteration if it happens within a specific time frame.
Ok, you speed once? $100. Twice $200. Thrice $400. And so on. We only reset if you don’t reoffend for any speeding in 5 years. If you want to speed 20 times in 5 years, ok, go ahead. You pay $52,428,800.
Bonus points for making it start at something relative to your salary. People will stop at some point out of self-preservation.
If you don’t believe high fines work, drive from Switzerland to Germany. In Germany the Swiss have no problem speeding, because the fines are laughable. While south of the border they behave very nicely on the street.
You could extend this to other crimes. Google and Microsoft happily pay fines, since it’s cheaper than what they make from breaking anti-trust regulations. If you doubled it on each infraction they would at some time start feeling the pain.
That is because in germany, cars are a religion substitute and just like there can be no speed limit on the Autobahn in general, there can be no real enforcement of speeding.
The fines actually increased a lot in recent years. Still cheap, though. And if there are radar cameras, they are often in places where speeding is quite safe to make money from fines vs places where speeding is actually dangerous (close to schools etc)
It is basically a archaic thing, the bigger the man, the bigger and louder his car and the faster he goes. It shows status.
So I imagine in New York City it works just the same. When the big guys like speeding and the big guys control the state .. then how can there be meaningful regulation of that?
(To confess, I like to drive fast, too. But not in places where kids can jump or fall anytime on the road)
The only problem was the two counties had shared but not integrated records systems with each other, as well the state drivers license authority. For two years, my cases got jumbled around the three systems, triggering plate and license suspensions which lead to me getting pulled over four times in that two year period.
It eventually all got sorted out without a lawyer. I didn't have to pay for anything beyond the first two tickets, and many hours on the phone. What was really notable was that by stop number four, from the perspective of the cop who pulled me over, I was someone who had been driving with suspended registration and/or license three times in a row. I was allowed to drive away three out of four times including the last time, and one time the cop would not let me drive, he waited with me patiently until my wife could be dropped off to get the car.
Maybe I'm just lucky, but to be honest I was surprised how not a big deal it was to anyone.
If you don’t pay the tickets, your car is at risk of being booted, but if you don’t park on the street or choose to obscure your license plate when you do (how did that leaf get stuck there!?), there aren’t many repercussions.
There was an attempt at a program to actually seize these cars, originally it would have kicked in at 5 tickets/year for immediate towing, but it was watered down to 15 tickets a year triggering a required safe driving class. They sort of half-assed the execution of that, then pointed at the limited results and cancelled it altogether. There’s an effort to pass a state law about this, we’ll see if it makes progress.
At the risk of hearing a depressing answer...why?
Don't get it twisted, I agree with you. The US is far too tolerant of dangerous driving. We are too dependent on cars for travel, and this is a consequence of it.
If you had 30 speeding tickets issued in person, it would be a lot different than 30 speeding tickets issued by machine.
If you go down to 0 points, your licence is suspended.
If you stay without a fine for long enough, you get back points.
The mechanisms for keeping people off the road are also just weaker in the US—I believe the penalties for driving with a suspended license are comparatively lighter, plus if your license is suspended you can often still get a "restricted" license that still lets you drive to work.
If the car's owner is a company, the company must declare a default conductor for this purpose.
Are you saying you can legally keep driving despite dozens of speed camera tickets in a year, as long as you keep paying the fines?
That's wild.
Around here (Melbourne, Australia), you'd lose your licence very quickly. A single speeding ticket is a minimum of 3 points off your licence (of which you have 12), and bigger infringements lose more points. So at most you could speed 4 times, but probably fewer. And it takes a few years for the points to come back.
Also, NYC has a different driving attitude than, say, Dallas. What people call aggression is often a difference in expectations. Drivers change lanes and merge far more assertively than in other parts of the country. As long as you aren’t causing the car behind you to panic brake, it’s considered acceptable. Hesitation from drivers tends to get more opprobrium than tight merges.
People block bike lanes and the box all the time. It’s annoying and you shouldn’t do it. But a lot of the rage is often unjustified. That FedEx truck needs to park somewhere and they aren’t going to roll over a fruit stand to do it.
It’s a dense, packed city. If you can’t give and take, you are going to hate it here.
https://www.youtube.com/watch?v=jeaHOe7eviQ
And not like running a late yellow, but a full on my-light-is-green-and-there's-a-guy-in-front-of-me-sideways
It has dropped a bit now though.
The trend I’ve noticed this year is turning right from the middle lane cutting off people in the turn lane.
Its possible for multiple lanes to turn without anyone cutting anyone off, but its also possible for people to turn right from the middle lane of the source street into the rightmost lane of the target street, cutting off people in the rightmost lane of the source street attempting to turn, or to make a right turn from a middle lane that is not allowed to turn, cutting of a legal right-into-any-lane from the rightmost lane when it is the only turning lane, so if someone explicitly says that's what they see and there is no available counterevidence that they are misreporting their observation, questioning it accompanied by a description of how it is possible for people to turn from multiple lanes into distinct lanes in harmony without anyone being cutoff is not particularly useful.
"its also possible for people to turn right from the middle lane of the source street into the rightmost lane of the target"
So you've created hypothetical situations that are no more useful than mine. I specifically mentioned having to turn into the nearest lane. If that's not true somewhere, then neither would adjacent turners be allowed. I simply asked if they were really cutting the other people off.
WTF, YOU made the comment: "If the right lane goes straight"
DUH.
Otherwise, it makes literally no sense, as you say.
Most people don't post utterly logically inconsistent ideas. Usually, they just screw up English and mean one thing when they say the other.
I saw another one where the car tried to turn right into an off-ramp with a line of cars waiting at the light. Like wtf, do you not see the wall of cars and headlights in front of you? Where are you going?!
The worst offenders are usually the older generations of countries where driving en mass is a recent thing. The old red guard uncles and aunties regularly run red lights cause who gives a damn about the law when you experienced the rule of the mob throughout your formative years. So parents and grandparents of students would be my guess.
[1]: https://pmc.ncbi.nlm.nih.gov/articles/PMC10149345/ [2]: https://newsroom.aaa.com/2024/08/the-pandemics-tenacious-gri...
https://calmatters.org/investigation/2025/12/california-road...
I remember the sad story of Michael Brown who was killed in 2014 while being arrested for selling loose cigarettes in Missouri. Today, at least in NYC, you see people parked out in front of the same corner every day selling weed and loose cigarettes. Same people, out in the open. I'm pretty sure that's not a sanctioned dispensary.
Just shows how much things can change in ten years. For whatever reason, police and prosecutors just gave up in enforcing any kind of laws. Seems like an overreaction to whatever problems we had with criminal justice
https://www.reddit.com/r/sanfrancisco/comments/11nbnxw/san_f...
https://en.wikipedia.org/wiki/Killing_of_Michael_Brown
Your article is just another version of pretending disparate outcomes is proof of discrimination. Totally wrong, but not what you say it's saying.
> Nearly a third of all shoplifting arrests in New York City last year involved just 327 people, the police said. Collectively, they were arrested and rearrested more than 6,000 times, Police Commissioner Keechant Sewell said. Some engage in shoplifting as a trade, while others are driven by addiction or mental illness; the police did not identify the 327 people in the analysis.
Not clear if that's only in 1 year, but 6,000 arrests for the same 327 people means 18 arrests per person on average. Maybe if you see the same person shoplifting more than 5 times you put him away for some real time. 10 times? Hell even 20 strikes and you're out would make a real dent and serve as a deterrent.
https://archive.is/VCKkk#selection-473.0-473.379
[Rhetoric "you" above]
There’s plenty of desire to increase prosecution rates in American jurisdictions but little desire to raise taxes high enough to pay for lawyers, judges, courthouses, and humane incarceration—let alone assistance for the otherwise innocent families of criminals. The victims of petty crime are usually poor or middle-class and therefore lack the political power to meaningfully change policy.
This is just not true. Most of this is organized exploiting a lenient justice system. From my original NYT article:
> Last year, 41 people were indicted in New York City in connection with a theft ring that state prosecutors said shoplifted millions of dollars worth of beauty products and luxury goods that were sold online.
The idea that these 300 people are just stealing bread to feed their families is a myth.
[1] https://www.brookings.edu/articles/retail-theft-in-us-cities...
But you might ask why are stores closing? Why is deodorant behind lock and key?
> Finally, corporate claims are not holding up to scrutiny, and are being used to close stores that are essential assets for many communities.
Ah yes, evil corporations like to close stores and forgo profit for ... reasons.
Don't believe what's right in front of your eyes.
Nothing to see.
> Ignore what's in front of you
Yes, the general advice is to look past specific notable anecdotes and try to identify actual data to validate whether your emotional experience of the world is reflective of the world or of you. In this case, the numbers suggest the problem is not the world, no matter how many videos you're seeing on TikTok or wherever.
A real problem for assessing truth in the modern world is that anything that happens anywhere is instantly available to you as a decontextualized short-form video, and it's your job as a responsible media consumer to understand that ten videos on your feed are not a trend outside your feed.
> Ah yes, evil corporations like to close stores and forgo profit for ... reasons.
No, they're not forgoing profits, they're choosing to close stores with lower levels of profits than they'd prefer and using retail theft as an excuse. It wouldn't be the first time and it sure won't be the last time that a business tries to deflect blame for its poor planning onto the rest of us.
Wealthy people (mostly) didn’t own the Kias and Hyundais that were stolen en masse during the early 2020’s for instance.
https://en.wikipedia.org/wiki/Kia_Challenge
They got what they wanted--fewer Blacks shot by the police. But that's because the police weren't being as aggressive in doing their job. Crime rates went up, the number of Blacks killed went up--fewer by cops being offset by more from other criminals.
And we see the result of bail reform. The old system was not good--for lesser offenses they were typically sentenced to time served. This amounts to skipping over the determining guilt part of "justice". But when they took action on that they didn't notice that that was what was actually keeping them off the streets. The justice system simply does not have remotely the capacity to actually prosecute as many crimes as they catch.
https://cdnc.ucr.edu/?a=d&d=DS19750820.2.20
Since then, the SFPF have always had a culture of being above the law. The monopoly on legal violence thing can be taken a bit too far.
We should not tolerate the ignorant and ineffectual response from lawmakers on this issue. Year after year, they refuse to do the right thing: make texting a DUI-level offense, with the same penalties. You could even argue that texting while driving is worse than DUI: Drunk people suffer from impaired judgment; sober people texting have decided to endanger and steal from everyone else while in full command of their faculties. It's despicable.
But we still need to address the rest. Radio is chokefull of ads and the usual radio content is often insufficient to overcome my loneliness, so I’m not gonna say it’s ok, but I listen to Youtube videos while driving. You can sanction me. But let’s make the radio less boring for the sake of safety.
As far as driving goes, any amount of drugs or alchohol is going to reduce reactions times, in addition to any impaired judgement or ability to control the vehicle. Even a couple of 1/10ths of a second in increased reaction time is enough to make the difference between braking in time and hitting another car or pedestrian/etc.
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