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Transportation Technology

With Pot Legal, Scientists Study Detection of Impaired Drivers 608

Hugh Pickens writes "A recent assessment by the National Highway Traffic Safety Administration, based on random roadside checks, found that 16.3% of all drivers nationwide at night were on various legal and illegal impairing drugs, half them high on marijuana. Now AP reports that with marijuana soon legal under state laws in Washington and Colorado, setting a standard comparable to blood-alcohol limits has sparked intense disagreement. Unlike portable breath tests for alcohol, there's no easily available way to determine whether someone is impaired from recent pot use. If scientists can't tell someone how much marijuana it will take for him or her to test over the threshold, how is the average pot user supposed to know? 'We've had decades of studies and experience with alcohol,' says Washington State Patrol spokesman Dan Coon. 'Marijuana is new, so it's going to take some time to figure out how the courts and prosecutors are going to handle it.' Driving within three hours of smoking pot is associated with a near doubling of the risk of fatal crashes. However, THC can remain in blood and saliva for highly variable times after the last use of the drug. Although the marijuana 'high' only lasts three to five hours, studies of heavy users in a locked hospital ward showed THC can be detected in the blood up to a week after they are abstinent, and the outer limit of detection time in saliva tests is not known. 'A lot of effort has gone into the study of drugged driving and marijuana, because that is the most prevalent drug, but we are not nearly to the point where we are with alcohol,' says Jeffrey P. Michael, the National Highway Traffic Safety Administration's impaired-driving director. 'We don't know what level of marijuana impairs a driver.'"
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With Pot Legal, Scientists Study Detection of Impaired Drivers

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  • by Anonymous Coward on Wednesday November 21, 2012 @09:20AM (#42054043)

    I know this is going to be a really odd way to detect impared drivers as far as people think but it is quite imperical and correct. You simply have the person do a coordination test with a video game type device. Impared drivers will show up whatever the reason. This can also be determined by blink rate and by detection of eye movements. It can be done very rapidly and has been in use by some municipal bus systems for some time with quite spectacular reductions in accidents. In fact this could be built into cars and we could have the car simply park if the driver is impared. (WOW! No arrest needed!) How about this wild idea. Skipping the police and stopping filling our jails and stopping all the fines etc while achieving the goal of public safety. It detects all types of imparement and doesn't bother wasting time on any other issue. Sleepy is detected too.

    This is going to get to be a moot point shortly as the cars will have things like advanced adaptive cruise control that essentially drives the car. How about Google's self driving car etc. I think we are going to ban driving of cars by humans very shortly as they simply are the most dangerous part of the car driving system. You know the NUT behind the wheel is the most dangerous part of the car.

  • Well... (Score:4, Interesting)

    by Anonymous Coward on Wednesday November 21, 2012 @09:21AM (#42054047)

    Here is my personal anecdote.

    I've been driving high nearly every day for almost 20 years, commuting at least 100 miles a day for 17 of those. I have never been in an accident & my last ticket (41 in a 30) was over 8 years ago.

    I don't drink & drive at all, that shit is dangerous.

  • by TheRaven64 ( 641858 ) on Wednesday November 21, 2012 @09:22AM (#42054053) Journal
    The blood alcohol level is a red herring. It correlates with impairment, but a number of other factors also affect it. The test should be for reactions and situational awareness. If you fail for any reason, then you should be prevented from driving. If you fail and also have been taking drugs that are known to cause this kind of impairment, then you might get some extra penalty.
  • by sunderland56 ( 621843 ) on Wednesday November 21, 2012 @09:33AM (#42054131)

    This. Right now if someone hits and kills a pedestrian, it's called an "accident" and they go free if they're sober - but they go to jail for many years if they had a drink. It doesn't matter that incompetent driving caused the death - the only time a driver is punished appropriately is when they had a drink.

    A test for competency would also get a lot of older drivers who cannot drive safely any more off the road.

  • Re:Well... (Score:4, Interesting)

    by xclr8r ( 658786 ) on Wednesday November 21, 2012 @09:38AM (#42054193)
    I'm sure as you well know.. different people are affected in different manners by THC consumption. Some get overly paranoid, some overly talkative, some think everything is ground breaking new idea, and some do become worse drivers. I've witnessed someone become impaired while smoking when s/he thought that there was no affect on his/her driving. There definitely was an impairment particularly merging on highways with those massive looping turn-arounds. I made the individual stop and took over after a heated argument.

    Am I saying your impaired? No... but there are some people who can't handle themselves and aren't aware that they are not in full control of their faculties.

    I just really hope fork lift drivers in the big box hardware stores are careful and don't use right before their shift. However, I expect to see accidents here. I'm glad this has been legalized in those states but hopefully this is enjoyed responsibly.
  • Re:Easy (Score:0, Interesting)

    by Anonymous Coward on Wednesday November 21, 2012 @10:27AM (#42054717)

    They didn't Decriminalize it; they LEGALIZED it.

    There's a difference.

    Decriminalize - its no longer a crime
    Legalize - its no longer a crime

    If something is not a crime, then its legal.. Right?

  • Re:Nonsense (Score:4, Interesting)

    by betterunixthanunix ( 980855 ) on Wednesday November 21, 2012 @10:33AM (#42054771)
    The real answer is to improve public transit, so that fewer people drive. Sure, people are going to need to drive around in rural areas, but we have a problem with impaired drivers in densely populated areas -- a problem that would be address by expanding public transit. Ultimately, the solution to impaired driving is to simply not have people drive -- but for the time being, we can pay people to drive buses, and we can focus our impairment tests on those people.
  • by RazorSharp ( 1418697 ) on Wednesday November 21, 2012 @10:40AM (#42054859)

    I think the problem is that every time someone's been in a crash and pot was found on them or they tested positive for pot at the hospital, the authorities "associated" pot with the crash. This is a classic mix up of correlation and causation. They don't realize that pot is found on a lot of people who are involved in crashes because it's so ubiquitous, not because it actually causes people to wreck.

  • by MakerDusk ( 2712435 ) on Wednesday November 21, 2012 @10:45AM (#42054909)
    I agree, in my city: the drunks drive fast, the pot heads drive slightly below the speed limit and follow every road law to the letter out of paranoia of being caught. Or they just chill at home... you know... half forming ideas to the point where there's usually a group of them to try to complete it.
  • by tehcyder ( 746570 ) on Wednesday November 21, 2012 @10:48AM (#42054941) Journal

    problem is, it is true;there have been independant studies of driving under marijuana influence and the subjects generally drive slower, tend to be over cautious, and realize they are impaired,which results in less driving errors.(sometimes even making less errors than when they are straight).In contrast to alcohol where subjects drive faster, are less cautious, and dont believe they are impaired.This is why the anti-pot advocates dont usually use marijuana driving stats for their cause.

    That is pure bullshit, driving too slowly and over-cautiously can cause accidents just as much as speeding and recklessness. Whenever there are stories about speeding, everyone rushes to say this (and it's true). But because this is the wonder-substance pot, there can be no possible bad side effects, so paranoia is just "being careful" and the inability to gauge speed correctly is just "taking things slowly".

    I'm all in favour of drugs, it's most fucking drug users that annoy me.

  • by crazyjj ( 2598719 ) * on Wednesday November 21, 2012 @11:04AM (#42055153)

    marijuana use in the absence of other substances impairs driving very little

    Yeah, my stoner roommate used to say shit like that too. Of course, he also claimed it helped him study, but unless one considers watching the Cartoon Network all day "studying" then I never saw any evidence of it. And, while I never was a full-time stoner myself, I did smoke enough to know that I sure as shit wouldn't have felt comfortable driving on it (or doing anything else that required concentration).

    Of course, I'm sure the stoner brigade can produce a plethora of studies claiming that weed is a fucking miracle cure-all with no downsides whatsoever, written by the same kind of biased researchers that produce studies showing that burning shit-tons of coal is great for the environment.

  • by rgbatduke ( 1231380 ) <rgb@ph y . d u k> on Wednesday November 21, 2012 @11:13AM (#42055299) Homepage

    Bear in mind also that the normal risk of fatal crashes is low, so doubling it is doubling a number very near zero as it is.

    Contrast that with alcohol (quote from a 1991 NIH article):

    "Based on driver fatalities in single-vehicle crashes, it was estimated that each 0.02 percentage increase in the BAC of a driver with non-zero BAC nearly doubles the risk of being in a fatal crash."

    That is probably not quite a beer's worth of alcohol for most body weights. So to put it another way, somebody who smokes pot while driving -- not "before", but during (a thing that in my youth I did with remarkable frequency) -- is roughly as impaired as if they had had just consumed a single beer. At those levels one does have to wonder about the error bars in the study -- statistically resolving one near-zero from another near-zero is actually remarkably difficult and requires ever so many samples and a totally unbiased sampling scheme with a complete lack of confounding variables -- so your assertion that the actual risk might even go down in those that aren't smoking pot and drinking a beer (where the latter is also difficult to detect and also doubles your risk all by itself) is not without possible merit.

    Again from the article here: []:

    "At BACs in the 0.05-0.09 percent range, the likelihood of a crash was at least nine times greater than at zero BAC for all age groups. Younger drivers with BACs in the 0.05-0.09 range had higher relative risks than older drivers, and females had higher relative risks than males. At very high BACs (at or above 0.15 percent), the risk of crashing was 300 to 600 times the risk at zero or near-zero BACs."

    Note that at BAC's that are still in the legal range in most states, single car fatalities are nearly an order of magnitude greater than the single "doubling" of risk for immediate use of marijuana. That strongly suggests that the best thing to do about "impairment" from marijuana is -- ignore it, or as suggested above, use a field sobriety test, not a blood or saliva test. It is more or less irrelevant to driving skill. I would say (again, based on extensive experience) that this is not entirely true -- one can eat or smoke enough, potent enough, marijuana that driving is ill-advised, but in those cases field sobriety tests would be nearly impossible to pass as well. But it is actually somewhat difficult to get that stoned, and most pot smokers that I knew didn't want to drive when they were -- too scary.

    But the simplest proofs are this. Whether or not it is legal, smoking pot and driving has been nearly universal forever among those that smoke pot. Most states are utterly unable to test for it, yet estimates of prevalence of usage (almost certainly low) suggest that anywhere up to 1/3 or 1/2 of people in certain age ranges at least occasionally smoke. Yet there is no positive association with this same group being a high risk on the road, outside of its tendency to drink. Alcohol is indeed a dangerous substance when it comes to driving, for obvious reasons, even for relatively small amounts. Pot is not, not until consumption is at extreme levels.

    The last thing that confounds this is age. The distribution of fatal and non-fatal accidents with age is quite scary. A stoned 40 year old -- I mean a seriously wasted 40 year old stoner -- with a risk of accident 3 times his age-linked norm -- is a safer driver than a stone cold sober 19 year old. "Silverbacks" -- drivers on the high side of 75, where one's eyesight, hearing, and brain are all breaking down -- are safer still. Why? Because they drive (sober or not) carefully, and in particular far more conservatively than younger risk taking overconfident drivers. I'm living through my own sons' driving experience -- one at age 17 has his first car, now multiply scarred from driving it a whole month. One now 22, who at 18 took his eyes off of the road

  • Not exactly (Score:4, Interesting)

    by gwolf ( 26339 ) <[gro.flowg] [ta] [flowg]> on Wednesday November 21, 2012 @12:57PM (#42056805) Homepage

    Drug posession and use were decriminalized in Mexico (where I live) in 2009. *All* drugs. However, growing and selling them is not legal, and is criminal. What does this mean?

    If I am found carrying or smoking a pot cigarrette (or injecting a heroine dose, or whatever), I am not a criminal — I might be a candidate for psychiatric help at some institutions, yes (most probably if I'm a reincident), but not going to jail.
    If I have 60 pot plants at home, i am not only doing something illegal, but a criminal offense.
    If I have over the allowed dose for personal use, I am (probably?) trying to sell it, and it is a crime.

    Not that our situation is ideal. Far from it. I believe full legalization is the only way out. But at least, it shifts the penalization to the real wrongdoers in our current situation.

  • by daemonenwind ( 178848 ) on Wednesday November 21, 2012 @04:44PM (#42059727)

    Signing a secession petition is a complete cop-out.

    You are right that the best reasons to exit the USA have nothing to do with the individual candidates and everything to do with the nature of Federal abuse of power.

    There are 2 courses which might be effective:

    1. You begin to actively work/campaign for the education of the people and the election of representatives who will advance your view of the correct limits of Federal power. Keep in mind that many candidates will be imperfect but still worthwhile; we did not get to where we are in 1 step, and we will not return from it in 1 step either. Baby steps must be acceptable, especially early on. This is the work of generations, as it took generations to get to where we are. You will need to be patient and diligent - and both qualities are rare in humans. In time, the USA will begin to resemble the ideas we suppose to claim, but the path will be long, difficult, and messy, as people unlearn their domestication and become, once again, wild and free.

    2. Carve out a piece of property - preferably on a national border or ocean. Define a government for yourself and those with you, and defend it with such skills and weapons as you have. This will be the all-consuming work of a lifetime, quite possibly in a shack in the woods in Montana.

    A petition to Obama to "Let My People Go" is the act of a crybaby, because it puts the work of implementing either option to other people who have no interest in seeing it through. Note that every state - yes, even Texas - which has sufficient signers has seen their Governor come forward and denounce the notion. The real task of secession and new independence is immense, and no person in power who you might Petition wishes to pursue it. They have far too much investment in the way things are.

    Therefore, you will do it yourself or you will not see it.

    As a point of deeper personal editorial, if you agree with the above and see sense in it, you had no reason to vote for anyone but Romney for president. He was far from perfect, but he had a legitimate shot and would begin walking back some of the worst excesses. Ron Paul has some nice ideas, for example, but one does not go directly from starvation to feast; indeed, attempting to do so would bring the worst strawmen of the opposition to life. Romney was not the man to take us back to the way things should be, but he could have been the man to start. Barack Obama is certainly headed for more federal power, not less. This is plain. Those who cannot hold their nose, in politics, are doomed to suffocate.

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