Marijuana By Itself Not a Significant Factor in Fatal and Injury Crashes in 2012, DPS Data Shows

Categories: Weed

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Image: Jamie Peachey
Pot by itself was not much of a factor in injury and fatal crashes probed last year by the Arizona Department of Public Safety.

Fewer than 1 percent of suspected impaired drivers involved in such crashes tested positive for nothing but marijuana.

New Times' findings, based on a records request satisfied by DPS this week, jibe with statistics we reported earlier this month in our feature article about Arizona's zero-tolerance marijuana-DUI law (link below). Drivers suspected of impairment in crashes that hurt or killed people in Phoenix, Chandler, and Scottsdale were rarely found to be impaired by marijuana, our earlier research showed.

See also - Riding High: Arizona's Zero-Tolerance Stance on Pot and Driving

- How to Avoid a Marijuana DUI in Zero-Tolerance Arizona

- Feds Want Blood-Alcohol Level for DUIs to Drop From .08 to .05

Alcohol is believed responsible for five to 10 times the number of crashes caused by drivers impaired by all other illegal drugs combined, according to the annual "Crash Facts" report put out by the Arizona Department of Transportation.

With medicinal herb now legal under state law for more than 37,000 people, we figured we'd find out what fraction of those drug cases involved pot. Not many, it turns out.

Studies have shown that marijuana may increase the risk of a crash -- a point highlighted recently in a newspaper column by Yavapai County Attorney Sheila Polk and Valley-based anti-pot activist Carolyn Short warning of pot-caused carnage.

The concern seems rational. But data from the observations of state troopers and police don't seem to support fear of a looming disaster on the roadways.

In 2012, blood and urine tests ordered by DPS crash investigators prove that alcohol was the culprit in the vast majority of the 335 injury and fatal crashes involving impaired drivers.

Lab tests showed that only three of the 335 suspected impaired drivers had marijuana and nothing else in their bloodstreams.

(Quick caveat before we dump our numbers on you: Gleaned from the lab reports, they mix injury and fatal crashes -- we didn't see the entire crash reports -- just the drug and alcohol test results. The numbers don't include the fatal crashes in which the suspected impaired driver died. We omitted one report because, confusingly, it showed two suspects. In about 10 cases, two BAC readings were given, possibly taken from the suspect at different times -- we always picked the higher one.)

Here's what we found:

* 335 -- total suspected impaired drivers. These are the folks busted by DPS statewide in 2012 for suspected impaired driving after an injury or fatal crash, and for which tests for drugs, alcohol or both were performed.

* 3 -- THC or THC metabolite only. The inert carboxy-THC metabolite, which can remain in the bodies of some users for weeks, was found in all three cases, at nanogram-per-milliliter levels of three, 39 and 42. The suspect with the 42 ngs of carboxy was also reported to have 2 ng/ml of active THC. The new legalization law in Washington sets an active THC limit of 5 ng/ml for drivers -- the same amount approved recently by Colorado lawmakers but not yet signed into law by Governor John Hickenlooper.

* 285 -- alcohol-only cases. If the observed level of impairment matches the BAC shown in a breath test, police don't typically order a more expensive blood test. It's a safe bet that some of those 285 drunk drivers also had drugs or drug metabolites in their bloodstreams, including pot.

* .173 -- average BAC of the alcohol-only cases. That's about halfway between an extreme and a super-extreme DUI in Arizona. Nothing higher than .382 and with a low of .01.

* 22 -- BACs below .08, of the alcohol-only cases. This week, the National Transportation Safety Board asked all 50 states to lower the legal limit to .05.

* 19 -- mixed THC with booze or other drugs. Meth shows up a few times here, but booze and tranquilizers are the most common.

* 6 - mixed alcohol and other drugs, but not THC.

* 15 -- drugged, but no THC or alcohol. Tranquilizers, sleeping pills, meth, morphine, pain pills.

* 7 -- negative drug and alcohol test results.

Notes in four of the cases suggested police believed impairment was caused by something the lab couldn't test for, such as spice, K2, and LSD.

Final word: All of the cases involved pain and suffering caused by a driver who was probably impaired by something.

Drive safely.

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40 comments
dana1974
dana1974

And the thing is, the test for marijuana shows the METABOLITES of THC, last I heard, not the actual THC itself.  In other words, there is no marijuana equivalent to the breathalyzer test for alcohol.  So these people testing positive for nothing but marijuana may not have even been impaired by it.

(And that's the problem with workplace drug tests too!  All they tell you is someone smoked weed in the past thirty days.  Doesn't mean they're high right now or even high at work!  What are the workplaces going to do if this drug is ever legalized?  Find themselves in court for wrongful termination, is my guess... good luck with that!)

kevin_hunt
kevin_hunt topcommenter

Please go fuck yourself,  Carolyn Short!!

“At the present time, the evidence to suggest an involvement of cannabis in road crashes is scientifically unproven. REFERENCE: G. Chesher and M. Longo. 2002. “Cannabis leads to a more cautious style of driving.  Cannabis alone, particularly in low doses, has little effect on the skills involved in automobile driving.” REFERENCE: Canadian Senate Special Committee on Illegal Drugs. 2002. Few studies report increased accident risk. REFERENCE: UK Department of Environment, Transport and the Regions (Road Safety Division). 2000. There is no evidence that consumption of cannabis alone increases the risk of culpability for traffic crash fatalities or injuries for which hospitalization occurs, and may reduce those risks. REFERENCE: M. Bates and T. Blakely. 1999. “Role of cannabis in motor vehicle crashes.” Epidemiologic Reviews 21: 222-232.  The more cautious behavior of subjects who have received marijuana decreases the impact of the drug on performance, whereas the opposite holds true for alcohol.” REFERENCE: A. Smiley. 1999. Marijuana: On-Road and Driving-Simulator Studies. There was a clear relationship between alcohol and culpability. In contrast, there was no significant increase in culpability for cannabinoids alone. REFERENCE: Logan, M.C., Hunter, C.E., Lokan, R.J., White, J.M., & White, M.A. (2000). There was no indication that cannabis by itself was a cause of fatal crashes.” REFERENCE: K. Terhune. 1992. The incidence and role of drugs in fatally injured drivers. Washington, DC: US Department of Transportation National Highway Traffic Safety Administration, Report No. DOT HS 808 065.

Coinspinner
Coinspinner

So marijuana that has been used for 50 years isn't a problem on the road?   

Common sense and 1,000,000 activists and highway safety data and insurance companies have been saying just that for years.

JohnQ.Public
JohnQ.Public

Interesting stats..5% of Arizonans can legally use marijuana yet it was involved in 1% of the crashes you reviewed. That would suggest that the accident rate involving marijuana is running double the percentage of the population authorized to legally use it. That would be an inaccurate and dishonest analysis BUT it clearly shows how the numbers can be manipulated by both you and Polk to prove whatever point you're trying to make. It does show, however, that there are fatal accidents that could potentially be attributed to THC and those accidents are likely to increase as legalized use increases. Will it be as bd as lcohol? I don't know the answer to that but it's clearly not completely harmless as you like to proclaim.

yourproductsucks
yourproductsucks

" If the observed level of impairment matches the BAC shown in a breath test, police don't typically order a more expensive blood test. It's a safe bet that some of those 285 drunk drivers also had drugs or drug metabolites in their bloodstreams, including pot."

This portion of the article cannot be overstated.  I understand the argument is attempting to state that marijuana alone is not impairing drivers.  Fact is, marijuana is rarely the only drug on board.  The presence of marijuana accentuates a person's impairment when mixed with another drug or metabolyte. 

Don't forget, marijuana is an illegal substance.  Those who use marijuana tend to use other illegal substances as well.  Tweekers are never without a nub.

If a person's impairment can be attributed to the presence of alcohol, no attempts are made to determine the presence of other drugs or metabolytes.  It's SOP.  

mandymountain
mandymountain

We already knew that the pot related parts of the Arizona DUID law were based on something other than public safety. Thanks for illustrating this!

jnovak51
jnovak51

Very well written, and researched article!  

brinvinn
brinvinn

lol, tell me something I didnt already know. Pot is cool liek that!


www.Prox-Anon.tk

Zachary Ankeny
Zachary Ankeny

triple-negative-city with the headline. I couldn't figure out the equation, but it got me to read the story, so well done.

robert_graham
robert_graham topcommenter

And neither was alcohol. Oh pleeze!

kevin_hunt
kevin_hunt topcommenter

@dana1974 Companies have already responded with saliva tests that go back 24 hours.

kevin_hunt
kevin_hunt topcommenter

@JohnQ.Public You fail to acknowledge that more than 5% of the population uses marijuana illegally.

“Comparing traffic deaths over time in states with and without medical marijuana law changes, the researchers found that fatal car wrecks dropped by 9% in states that legalized medical use.”

Source: Medical Marijuana Laws, Traffic Fatalities, and Alcohol Consumption  by D. Mark Anderson, Daniel I. Rees (November 2011) 

ray.stern
ray.stern moderator

@JohnQ.Public Your "analysis" isn't dishonest or inaccurate -- it's just nonsensical. For one thing, there's no question that way more people use marijuana illegally than legally in Arizona. If the number of Arizonans using marijuana is 2 percent of the population, by your "dishonest" analysis that means the "accident rate" is half the percentage of those using pot, which sounds less drastic than your "running double." But most importantly, you mistakenly conclude you can say anything about the "accident rate" with these stats. You can't, because to get a true accident rate you'd need to add in the cases that don't involve suspected impaired drivers.

I'll admit my analysis is far from perfect. But I believe the data does show that typically, when a cop goes out to the scene of a serious crash and suspects a culpable driver of impairment, it is very unlikely (ie., a 1 percent or less chance) that the impairment will turn out to be just pot. I don't believe I proclaimed anywhere it was "completely harmless" for drivers. It's certainly less harmful for drivers than booze, though, in my humble opinion.

Flyer9753
Flyer9753 topcommenter

@yourproductsucks 

False

" Those who use marijuana tend to use other illegal substances as well"

100% assumption there that is not born out of facts.

This assumption comes out of studies that state, correctly, that most harder drug users/abusers started or at some point used MJ. No one is denying this. One of the common problems however with these studies is that they only look at the problem from 1 perspective, the perspective of the hard drug user looking backwards in time.

However, that's not the entire story, since studies have also shown that the majority of MJ users do not use other drugs. Studies done of MJ users in the general population prove this.

For example (not actual numbers, for example purposes only): Say you survey 1000 people who stated they have used MJ. Out of those 1000, 300 say they have used other harder illegal drugs.

Now say you survey 1000 people who have used harder illegal drugs and 800 of them state that they have used or started with MJ. 

Both are true, but if you only look at the second one, which is what is commonly done in these arguments, it looks like 80% of all marijuana users move onto hard drugs or do other illegal things. 

This argument is the only one that gets used by the anti-MJ crowd, even though it only tells a small part of the entire story. This is the same argument you are trying to use when you say that because someone does 1 thing that is illegal, they must therefore do other things that are illegal.

I bet I could find many things you do that are illegal, does that mean you are going to do other illegal things? No, that would be an assumption, not fact and not science.

You also mention metabolites. MJ metabolites cannot be used to indicate intoxication since MJ metabolites, unlike most other drugs, stay in the body for up to 90 days whereas the other drugs metabolites are often flushed in 72 hours. Metabolites do not get one high or impaired nor keep one high or impaired

btw - my numbers above are not the actual numbers, but they are not far from the actual ones either.

yourproductsucks
yourproductsucks

...and the above quoted statement is misleading.  The more accurate statement is that if a person's impairment can be attributed to the presence of alcohol then no other tests are given to determine other drugs or metabolytes.

Imagine if it were the reverse and as soon as marijuana was determined to be "on board" any other drug or metabolyte would be ignored; now that would certainly schew the numbers.  This issue alone debunks the entire argument made by Mr Stern. 

teknik
teknik topcommenter

@JoeArpaioFan look at the tests that have been done on cannabis and driving.


the simple fact is that it doesn't impare one's ability to drive a car.


It's the safest intoxicating substance on the planet.  There's a reason God gave it to us and people like you, who seem to be working against making life a better place and our world a better place for humans to reside in.


People like you and your nanny state government running around and acting like you are for personal liberty make me sick.



JohnQ.Public
JohnQ.Public

"There are lies, damned lies and statistics." Mark Twain. I wasn't doing any analysis - my point was that each side in this debate will manipulate the stats for their respective purposes and all of those analyses are likely to be an inaccurate and dishonest to prove a point. Polk's analysis was inaccurate. You're analysis wasnt much better. I was just trying to make the pont that the stats are easy to manipulate by both sides. BTW, you're the one who quoted the number of card holders as if it were a meaningful statistic. Specifically, you said that, "With medicinal herb now legal under state law for more than 37,000 people, we figured we'd find out what fraction of those drug cases involved pot. Not many, it turns out.". Why'd you bother to cite the number of cardholders in the article but proclaim the number to be meaningless in the comments? It seems like you liked that stat when you thought it worked in your favor but when I pointed out that the math didn't necessarily work in your favor you now want to use a different metric. Again, I'm just trying to point out how both Polk and you are trying to manipulate o cherry-pick the numbers to prove the point you're each trying to make.

yourproductsucks
yourproductsucks

@Flyer9753 I understand how my conveyence of thought could have been interpreted the way you took it.  Better said, those who abuse illegal substances tend to also use marijuana. 

Tweekers almost always attempt to balance their high using marijuana.  Those that speedball tend to incorporate marijuana.  Often marijuana is used with alcohol.  Even paint sniffers use marijuana to even out.  Those who abuse hallucinagens are prone to marijuana use as well.  Those that use marijuana and then "graduate" to harder drugs, rarely leave marijuana behind. 

This "assumption" is borne out of years of experience in dealing with addicts of all kinds.  There is credence to the gateway drug theory, yet it has nothing to do with the statements I made regarding substance abuse.

ray.stern
ray.stern moderator

@yourproductsucks There's nothing misleading about the statement you quoted from the article. Your statement is similar and isn't any more accurate.

Where you depart from reality is when you claim that pot users tend to use other illegal substances as well. I don't know what gives you that impression. The 2012 Arizona Criminal Justice Commission report, for instance, shows that far more young people admit to using marijuana than other illegal drugs. Judging by that, pot users do not tend to use other illegal substances.

Beyond that, you must know that the presence of pot metabolites doesn't reveal impairment the way a breath test reveals booze impairment. Having a few ng/ml of carboxy-THC in your bloodstream doesn't mean close to the same thing as blowing a .20 in a breathalzyer. You may or may not be right that the THC is causing further impairment just because its presence is detected.

Recall that the alcohol-only group had an average .173 BAC. That's enough to cause a crash by itself. I guess you're arguing that a significant percentage of that group also had THC on board, and that the THC is what put them over the edge to cause a crash. I think that's a stretch.

marcy
marcy

@teknik @JoeArpaioFan 

It is completely incorrect to state that pot doesn't impair driving, it quite clearly does.  What is doesn't do is impair driving 10 days after you smoke it.

sliperymike
sliperymike

@teknik @JoeArpaioFan you said it dude,this JAF is a douche troll

Flyer9753
Flyer9753 topcommenter

@teknik @JoeArpaioFan  

JAFfy doesn't want a nanny state, he wants a control state, so long as he is the one in control.

Nanny state implies the nanny has some interest in the care of the ones they are nannying, some interest in that person's well being.

JAFfy doesn't give a damn about the ones he can control, he gets off on the control aspect alone. He and those like him are convinced of their own 'right' to control others, nothing more.

Flyer9753
Flyer9753 topcommenter

@ray.stern @JohnQ.Public  

I'm not going to comment on this discussion you are having with JQP.

I just wanted to say, and ask that you pass this around to the other writes at NT, that I am very happy to see you and the other writers taking what appears to be as of late, a more active role in the comments sections of your articles. 

I think dialoge is always a good thing and it shows an interest after the fact of the story actually being published. 

I hope you and other NT writers/staffers continue to do this.

ray.stern
ray.stern moderator

@JohnQ.Public @ray.stern Well, okay, but I did not "manipulate" any stats or data -- I presented to you what I found, and you and anyone else is free to go to DPS and double-check my work if you don't believe me. I also did not discard any data I found inconvenient. And I disagree that I have a "pro-pot agenda." True, I believe there is no valid reason to throw people who possess pot in jail when they're caught, and I've also defended the wishes of voters in the 2010 election. But my "agenda" is, first and foremost, ALWAYS journalism. If the stats had shown 285 pot-only cases and 3 booze-only cases, I would have reported and opined on that stat. If the first pot overdose in history ever occurs, I would hope that I'd be the first to give that scoop to readers.


Other than that, you make some really good points.

JohnQ.Public
JohnQ.Public

@ray.stern That's interesting because I thought that your analysis or conclusion was the point of your article.   I didn't voice an opinion on the relative number of cases and still don't because I don't feel I have all the facts, especailly about how the data is compiled (I know - crazy, right). 

My only point is that each side manipulates the data and statistics to prove whatever point they're trying to make.  And then when the data they are using is no longer convenient to them, they will discard and find other data to cherry-pick or manipulate.  Polk has an anti-pot agenda and she will either manipulate the data or cherry pick it for her purposes.  Those with a pro-pot agenda and you're doing the same.   My point in playing with the numbers in my original post was to show how the math and the data can be manipulated to show that they mean something that they really don't mean - I guess I wasn't as articulate in making that point as I tried to be. 

ray.stern
ray.stern moderator

@JohnQ.Public My "analysis" or conclusions about the data isn't the point, anyway. We can agree to disagree on why there were 3 pot-only cases and 285 booze-only cases, instead of the other way around.

marcy
marcy

@yourproductsucks @Flyer9753 

Your assumption is backwards.

Most pot users are not users of other illegal drugs but users of other illegal drugs are very likely to also use pot.

Or, to put it another way that might clear it up for you.  Most people who use illegal drugs also eat cookies but most cookie eaters don't use illegal drugs.

Flyer9753
Flyer9753 topcommenter

@yourproductsucks@Flyer9753 

"Better said, those who abuse illegal substances tend to also use marijuana. "

Much better said, but I would simply ask that you add the addendum to that statement of ", but few MJ users graduate to other illegal substances." - which is true, especially so when you look at the 'legal' drugs for comparison.

Sorry to sound like I am beating a dead horse here, but it's an important piece of information and makes an important distinction, especially since most people do make assumptions and will make the logical assumption, based on the original statement, that the same would have to then apply to MJ, which helps to propagate the incorrect information about MJ that is so prevalent in society.

You are correct in the rest except your statement about the gateway theory having credence and we can discuss that too if you like.

Also remember that even though legal, every one of the ones you listed and others also rarely leave alcohol, caffeine and nicotine behind either.

ExpertShot
ExpertShot topcommenter

@ray.stern Pay no attention to him, he's an idiot.  His product truly sucks! Litte better than Joe Arpaio's Army (fan boi).

ray.stern
ray.stern moderator

@yourproductsucks @ray.stern 1. "...then no other tests are administered..." No, your statement isn't quite true according to cops I spoke with. They told that if the person's observed impairment doesn't match the BAC, a blood test might be ordered. That's why some of the results I saw included both BACs and drug results.


2.  "You can't use a test process that ignores the presence of marijuana to in accidents when alcohol is present to make the argument that marijuana doesn't impair your ability to drive."


Marijuana can impair your ability to drive, as I've previously written, so I'm not making the argument you claim I'm making. Besides that, you're not referring here to booze-only or pot-only cases, but to cases in which a drunk driver also has THC "on board." That might not be that many of the booze-only cases, and even in those cases it'd be tough to tell if the THC was the tipping point that caused a .173-BAC driver to crash.

yourproductsucks
yourproductsucks

@ray.stern Your statement suggests that tests to identify additional substances continue unless impairment matches the BAC.  That is wholly unfactual.  If the BAC meets or exceeds State limits (.08 or above) then no other tests are administered to determine other drugs present. 

In other words, if a person is a .08 or above, it doesn't matter to the State whether or not the person's impairment matches the BAC...it is already presumed they are impaired. 

You can't use a test process that ignores the presence of marijuana to in accidents when alcohol is present to make the argument that marijuana doesn't impair your ability to drive.

Cheech knows your argument is framed around bullshit.

http://youtu.be/tBW2aQFVzCU

ExpertShot
ExpertShot topcommenter

@marcy@teknik@JoeArpaioFanMarcy, which study are you citing for your statement that " . . . it quite clearly does."?  It does not "quite clearly" show that.  In fact it shows the opposite:

From a respected journal of experts in the field:

A 2002 review of seven separate studies involving 7,934 drivers reported, “Crash culpability studies have failed to demonstrate that drivers with cannabinoids in the blood are significantly more likely than drug-free drivers to be culpable in road crashes.”

http://norml.org/library/item/marijuana-and-driving-a-review-of-the-scientific-evidence

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