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Breath Test For Pot Being Developed At WSU

An anonymous reader writes with this news from Tacoma, WA's News Tribune: A team at Washington State University is working to develop a breath test that could quickly determine whether a driver is under the influence of marijuana. Law enforcement officers already use preliminary breath tests in the field to estimate drivers' blood alcohol content. But no similar portable tool exists to test for marijuana impairment ... Stoned drivers have become an increasing concern since Washington voters legalized recreational use of marijuana ... A quarter of blood samples taken from drivers in 2013, the first full year the initiative was in effect, came back positive for pot. ... officers and prosecutors rely on blood tests to determine how much active THC is present in a driver's blood. Those test results aren't immediately available to patrol officers who suspect someone is driving high." Also reported: "Under Washington's legal marijuana law, those who get caught driving with a blood content of at least 5 nanograms of active THC per milliliter are subject to an automatic driver's license suspension of 90 days or more."

5 of 342 comments (clear)

  1. Re:is it really bad in the first place? by blue+trane · · Score: 5, Informative

    From http://www.ukcia.org/research/...:

    Alcohol impaired performance relative to placebo but subjects did not perceive it. THC did not impair driving performance yet the subjects thought it had.

    Alcohol makes you more aggressively confident, pot makes you more careful of your driving.

  2. Re:is it really bad in the first place? by amiga3D · · Score: 5, Informative

    I've seen them do the same thing drunk as a skunk. So what? It's not the same thing at all. You can shut your eyes and play too. Try that behind the wheel.

  3. Re:is it really bad in the first place? by cold+fjord · · Score: 5, Informative

    Alcohol makes you more aggressively confident, pot makes you more careful of your driving.

    Not as such.

    Acute cannabis consumption and motor vehicle collision risk: systematic review of observational studies and meta-analysis

    Acute cannabis consumption nearly doubles the risk of a collision resulting in serious injury or death

    Effects on Driving:

    ... Marijuana has been shown to impair performance on driving simulator tasks and on open and closed driving courses for up to approximately 3 hours. Decreased car handling performance, increased reaction times, impaired time and distance estimation, inability to maintain headway, lateral travel, subjective sleepiness, motor incoordination, and impaired sustained vigilance have all been reported. Some drivers may actually be able to improve performance for brief periods by overcompensating for self-perceived impairment. The greater the demands placed on the driver, however, the more critical the likely impairment. Marijuana may particularly impair monotonous and prolonged driving. Decision times to evaluate situations and determine appropriate responses increase.

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    much of left-wing thought is a kind of playing with fire by people who don't even know that fire is hot - George Orwell
  4. Re: is it really bad in the first place? by Anonymous Coward · · Score: 5, Informative

    You don't get it. There's no way to reason with fearful idiots. They use words like 'multi ton vehicle' or imagery of bicyclists and such to try to get you imagining the worst things that can happen while suspendint critical thought.

    They KNOW that driving after smoking pot is every bit as bad as driving while massively drunk and no evidence to the contrary will convince them ever. It's the way the neoprohibitionists masquerading as safety groups got the blood alcohol limit lowered to .08 when it is a simple provable fact that accidents involving injury or death almost always involve a level of .12 to .15 or even higher.

    Yes, people with lower levels get into accidents but so do people who never drink. It's the spectacular multi car wrong way driving that these groups trot out in their quest for more restrictions even though more restrictions don't help because they don't address the problem. They just make some people feel good while ruining the lives of others.

    So a test for marijuana that actually measures levels of current activity vs a month ago COULD be a good thing, but the very first thing that needs to be shown is that there is an actual problem at a certain level.

    The only rational attitide here is to want proof and evidenxe before making a decision and the hell with either side's personal experience stories. .Meanwhile, expect the selfish moralizers to continue to engage in ad hominem attacks if you don't adhere to their prohibitionist mentality.

    it is worth noting that the first DUI laws were passed based on consensus from the medical community about actual levels of dangerous impairment. They were around .12, which is the magic number to this day above which almost all serious DUI accidents occur. That number has not changed. Science is kind of like that. The laws however have changed. You see, some people were driving after having a beer and not getting convicted. That is unacceptable to the moralisers of the world, so they threw science out on its ear and they keep pushing for a lower and lower restrictions, hiding behind the banner of motherhood for political reasons in many cases, even though there is absolutely zero evidence in favor of it.

    That is the sort of thing that people have to be on guard for here. With any substance, there is some level beyond which impairment put somebody in a position where they cannot perform the task of driving to minimum recognized standards. That is the level which needs to be prohibited. Anything else is just imposing your own fear or your own moral beliefs on someone else.

    There is of course an even a better method of solving this problem. That is the test for the actual problem instead of a proxy. There are devices and tests that can measure reaction times. They are used in industries that actually care about safety instead of the perception of it. What we really need is the ability for a driver to prove using one of these tests but he or she is not impaired. Then whatever substance at whatever level is irrelevant. Of course, actual scientifictest like that would drive the prohibitionists absolutely bananas even though it would be superior because it would also catch things like people who are too tired to drive safely. Of course, the prohibition is the don't actually care about that because for most of them the goal is to demonize whatever it is they don't like and whoever opposes them.

  5. Re:is it really bad in the first place? by The+Real+Dr+John · · Score: 5, Informative

    This is true and well known to the police, and scientists as well. Alcohol inhibits glutamate (excitatory neural) receptors in the brain, so the more you drink the more your brain's activities are depressed. So the more drunk you get, the more impaired your mental functions become, and the less motor control you have. Pot has virtually no effect on glutamate receptors in the brain. It acts on endocanabinoid receptors which are in a whole different class. They are involved in other functions, including hunger sensations, pain sensations, and memory. There is some speculation that this system may be involved in clearing old memories, perhaps to make room for new ones. So ironically, pot would probably be better than alcohol for people in bars drinking and trying to forget bad memories.But pot does not impair driving abilities, and tends to make drivers more cautious. Testing for pot in drivers should not result in a fine, or license suspension, it should result in a "have a nice day" response from the officer as he hands you your license back.

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    A brain is a terrible thing to waste... Mind? That's debatable.