Want to read Slashdot from your mobile device? Point it at m.slashdot.org and keep reading!


Forgot your password?

Steering Wheel Checks Alcohol Consumption 436

karvind writes "According to washingtonpost, Inventor Dennis Bellehumeur has made a $600 sensor that can be installed in a steering wheel or in gloves and will test a driver's skin to determine alcohol consumption. Bellehumeur, a real estate agent and deli owner in Wilton Manors, spent 12 years developing his sensor after his then-teenage son crashed into a utility pole while driving drunk and suffered minor brain damage. He received a patent this month and the sensor should complete testing this year."
This discussion has been archived. No new comments can be posted.

Steering Wheel Checks Alcohol Consumption

Comments Filter:
  • The Obvious (Score:2, Insightful)

    by fembots ( 753724 )
    Drunken driving accidents increase in winter because every senselessly drunken teenager not properly educated by their parents will be wearing branded non-sensored gloves.

    And will the car come to a stop if a person only starts drinking (and got drunk) after the car's moving?

    And will those drunken teenagers just steal some non-sensored cars which they're not familar to drive with?

    I think this "invention" is as good as the censorship card on cable TV, or that running shoes that power the TV. However the on
    • Re:The Obvious (Score:5, Insightful)

      by Anonymous Coward on Monday May 30, 2005 @05:45PM (#12678743)
      Having a light on your dashboard telling you that you're objectively too drunk to drive will probably help reduce drunk driving for rational people who overestimate their limits.
      • Re:The Obvious (Score:5, Interesting)

        by downsize ( 551098 ) * on Monday May 30, 2005 @06:03PM (#12678876) Homepage Journal
        this is true.

        we had a big new years party 4 or 5 years ago and we bought a breathalizer so people could see what they would blow.

        we used it for fun and gags, but ultimately, at the end, it saved people's lives (perhaps) and possibly even a few DUIs. towards the end of the party as the ones standing started to leave, they would blow and everyone that was over the legal limit called a taxi or worked out a ride with someone well under the legal limit.

        but this device is not the savior to teen drunk driving (which sounds like the reasoning behind the invention) - although it may cut down some incidents by 20% or so.

        bottom line, you just can't prevent people from being stupid - and it's not funny because most of the time it means the loss of life of another instead of the stupid one that caused it.
        • Re:The Obvious (Score:3, Insightful)

          by Total_Wimp ( 564548 )
          The breathalyzer at the party was a great idea. I've carried one in my car for some time so I can check myself as I leave bars, parties, etc.

          But the deal with teens is that their sense of not wanting to get in trouble far outweighs their sense of risk from driving drunk.

          When I was a teen, all the local teens went to this guy's apartment (behind the 7-11 and right across from the liquor store) to get him to buy them beer. I was in this apartment on many occasions when this happened and a very common occu
      • Rational Thought (Score:2, Insightful)

        by Renegrade ( 698801 )
        Here's a rational thought:

        One shot of hard alcohol = one wineglass of wine = one bottle of beer = one FULL hour not driving.

        Or if math is too hard:

        I've been drinking alcohol tonight. It does not matter how much, I will not be the driver.

        Or if an obsessive-compulsive "drinking and gadgets" disorder is present in the person:

        There's fifty thousand different types of alcohol analyzers out there that you can buy already. Buy one.
        • Re:Rational Thought (Score:4, Informative)

          by Tim C ( 15259 ) on Monday May 30, 2005 @06:32PM (#12679047)
          One shot of hard alcohol = one wineglass of wine = one bottle of beer = one FULL hour not driving.

          It's a nice idea, and sounds good as a guide, *but*:

          The way I pour/buy wine, one bottle gives you three glasses (250ml/glass). That means that three bottles of wine = nine full hours not driving.

          Believe me, I've had three bottles of wine on an empty stomach; I was barely in a condition to stand the next morning, let alone drive.

          In fact, it's perfectly possible to get drunk at night, feel fine in the morning and still be over the legal driving limit (at least in the UK, YMMV of course).
      • Kudos poster, excellent idea! Doesn't inhibit the car from moving but does act as a warning to the driver.
    • Re:The Obvious (Score:5, Insightful)

      by shawn(at)fsu ( 447153 ) on Monday May 30, 2005 @05:47PM (#12678765) Homepage
      Don't you ever get tired of looking for ways to blame the parents. You do realize that no matter how much you try to educate someone there is always the possibility that no matter what they will end up doing exactly what you told them not to. Children make mistakes and the law does provide for punishment of the parents for their children's actions. This guy goes out and makes a tool that might be able to help the situation and you jump all over it. It does have uses beyond teenage drunk drives you know that right. It could be installed at the request of a judge after an ADULT gets convicted of DUI. Hell I could go out and buy one just in case I don't trust my own opinion of whether or not I'm drunk. It doesn't have to be just a tool for lazy parenting as you like to make it sound.
      For the record I don't think it's lazy parenting, I think it's giving more tools to help parents. As Ronald Regan said "trust but verify"
      • Yes, what the hell are you all talking about kids for. Kids can be educated by their parents. This things is meant for ADULTS. Kids are usually not alcoholics who drink 50% of their time, while still carrying a driver's license.
      • Re:The Obvious (Score:3, Interesting)

        by DarkOx ( 621550 )
        The problem with DUIs are like anything punishment is neither swift nor sure. Its not possible to have swift and sure punishment in a free society either. You have to make up for that by where appropriate using suffcient threat as a deterant. DUIs are a good example because breaking that law endangers outhers not just you. DUIs place others in real danger too not some long shacky chain of events that cup of coffee you served me in that plastic cup 20 years ago gave me cancer, but I am dead because you c
        • Re:The Obvious (Score:3, Interesting)

          by aaronl ( 43811 )
          It looks like you are talking about a mandatory minimum sentence. Those are always a bad idea as they take the ability to lay down penalty away from the courts. Do you really want to start down that kind of road? So for now you have a penalty that seems justified for DUI, since drunk driving endangers people needlessly; do you then start similar sentences for other transgressions? Also, the ability for a judge to accept a plea is not only something that should be able to happen, but is a necessity in a
          • Re:The Obvious (Score:3, Interesting)

            Damn that Hammorabi guy. How dare he codify laws and take it out of the hands of whomever was overseeing the case!

            Do I want to take discression totally out of the hands of judges? No. But when you see 10-12 time offenders killing people (and the bums never doing a day in jail), then you have to think there is a problem with the system.

            The problem with judicial "discretion"? Leniency is disproportionally given to those with better resources. Take a look at a few state senators who have literally gotten awa
          • Re:The Obvious (Score:3, Interesting)

            by KiloByte ( 825081 )
            You don't want to ruin someone's ability to live for that period of time.

            Having your driver's licence revoked is not having your ability to live ruined. The inability to drive a car is just a minor inconvenience.

            I've been twice to the US, and I was shocked by the fact that someone not in a car is considered to be not a citizen. If you ask someone the way to something one street segment away, you get shown a long way around to the next parking lot, and then told the way from there -- people don't even r
    • NOT Obvious (Score:3, Insightful)

      by deft ( 253558 )
      Please, first of all... speak for the city you are in maybe, but around here we dont wear gloves int hwe winter.... 60 degrees just doesnt need it. And the occurences that you speak of.... the time its really cold and the drunk kid gets into his car (assuming its the glove setup and not the steering wheel one, which makes more sense) the car would probably just report back it cant get a reading.

      And then the work around is that most kids will STEAL A CAR??? please, what part of town do you live in that this
      • It is entirely likely that it will provide incentive to steal a car. A lot of kids steal cars and go joyriding. The majority of recovered stolen cars end up full of burger wrappers and such, they're usually just stolen for a joyride and abandoned when they run out of fuel.

        The real issue is that this is just another piece of crap that doesn't need to be installed in a car, and which can fail and cause it to not be startable. I hope and pray that manufacturers do not begin to offer something like this as st

    • Drunken driving accidents increase in winter because every senselessly drunken teenager not properly educated by their parents will be wearing branded non-sensored gloves.

      The article is very low on information, but since it could be installed in both steering wheel and gloves, maybe the car won't start without skin contact in either? So, if you want to drive, you will have to put your hands or gloves on the wheel, and then this test is performed.

      And will the car come to a stop if a person only starts dri

      • Rather than killing the engine of a moving car, which could present a whole new series of hazards, how about flashing the brake lights in a specific pattern, or some other externally visible indicator?

        I suspect that the knowledge that any officer within visual range could instantly tell that you were intoxicated would prove an excellent deterrant.
    • > If I had to go to jail when my kid killed someone under the influence, I would have had one kid instead of five, and spent more time on that one kid. If I can't afford the time, maybe I am not qualified to have kids at all?

      I'm all for parents trying to educate their children correctly, but that's a recipe for disaster if I ever saw one: parents becoming hyper-protective by fear of prison, severely damaging the children' capacity to lead normal lives and probably leading to extreme behaviour in reactio
    • I think this "invention" is as good as the censorship card on cable TV, or that running shoes that power the TV. However the only "reactive invention" that I would like to see is a law punishing parents who cannot educate, manner, guide and monitor their children.

      And I think you should have someone in your family killed by a drunk driver. I just want to make this entire post say F You to release some anger I've built up by reading your mindless post. This invention is great. If you're drunk, your car
  • Best of Luck (Score:2, Offtopic)

    by njcoder ( 657816 )
    A somewhat good news patent story on slashdot is a nice find. I hope he does well. It must be a terrible thing to have to go through what he went through and I hope he finds success in this and it brings him some comfort in that it may help others.
  • If I had just been cleaning things with alcohol, would it set this off?
  • YES! (Score:4, Informative)

    by Capt'n Hector ( 650760 ) on Monday May 30, 2005 @05:46PM (#12678757)
    Before anyone goes off about freedom being limited, rights, etc... come on. Nobody has the right to drive drunk.
    • by Anonymous Coward
      It's a priveledge, fetterd by many rules and regulations, including an allowable limit of alcohol in your bloodstream.
    • I have a right to drive in whatever condition I want. On my property. Of course this wouldn't be a violation of my rights anyway, since nobody (so far) is forcing me to use this steering wheel.
    • Nobody has the right to drive drunk.

      True, but that still doesn't make it right. I don't drive drunk, ever, but I am sure many legislators would still be happy enough to force this device on me, at my cost. This is just the government babysitting us again, and taking responsibility away from both the responsible and the irresponsible.

      Besides... I very much doubt that this will have any significant impact on road safety. Just like car safety inspections have not made the roads much safer, but only m

    • Re:YES! (Score:3, Insightful)

      by drinkypoo ( 153816 )
      I have the right to drive my car while drunk, so long as it is on my property.

      This is a real stretch, but let's say my e-brake is not set and my car rolls down a hill and pins someone to a building. It weighs 3500 lb, so if I have to push it up a hill, and I've been drinking so I can't start it and back it up, they're just fucked.

      Perhaps instead of mandating equipment like this someday, we could just actually start punishing DUIs properly. Why are there people with like eight or nine DUIs driving out t

      • Re:YES! (Score:3, Interesting)

        by ColaMan ( 37550 )
        Try living in australia.

        0.05% legal limit, which equates to roughly 3 beers an hour for the first hour, then 1 beer an hour after that.

        Just about every DUI results in a loss of licence for at least a couple of months. Caught driving while suspended? Whoops, 12 months no licence for you, dumbass. Driving again? Kiss your licence goodbye, permanently. Sure, you can apply to have it back in a few years, but you'll need a damn good case.

        Random roadside breath tests, pretty much every couple of days where I l
        • Re:YES! (Score:3, Insightful)

          by Osty ( 16825 )

          0.05% legal limit, which equates to roughly 3 beers an hour for the first hour, then 1 beer an hour after that.

          How much do you weigh? 4 beers in two hours would put most people over 0.05%, if not 0.08%. If you're planning a long night out, you'll metabolize most of those first three beers in a few hours and your subsequent "maintenance" beer/hour won't cause a problem. However, if you're going out for a 2 hour dinner you're not going to have time to metabolize those first three beers before it's tim

          • Re:YES! (Score:4, Insightful)

            by Cederic ( 9623 ) on Tuesday May 31, 2005 @10:18AM (#12683706) Journal

            Or how about you just don't drink and drive?

            Heard of taxis? Have friends? There are plenty of ways to go out for the night, have a drink, and avoid driving home.

            There's also nothing stopping you staying in and having a drink.

            Maybe the idiots that think they can drive when they've "only had a couple" should get a life and stop trying to ruin others.

            A .05% margin is sensible. It means people taking cold medicine (many brands here in the UK contain alcohol) wont be over the limit, it means people that ate a sherry trifle for pudding wont be over the limit, and it means that people that just slammed a triple tequila know they'd better not be on the road.

            There's no normal excuse for drinking and driving - it's a proven and easily avoidable cause of a lot of accidents and deaths.

            To get back on topic, would I want one of these steering wheels? To be honest, no - I don't ever touch my steering wheel unless I'm sober and I can't be bothered with the thing breaking, or failing to realise that it's not alcohol in my bloodstream, it's windscreen washer antifreeze that spilled while I was filling the car.


    • NO!!! (Score:4, Insightful)

      by Wolfger ( 96957 ) <wolfgerNO@SPAMgmail.com> on Tuesday May 31, 2005 @08:34AM (#12682943) Homepage
      I don't want to pay for a $600 gadget that can be defeated by a $10 pair of gloves! Cars are expensive enough already without sticking worthless tech into them for the sake of putting on appearances.
  • ...who's going to pay for this?

    It seems to me short of a court order, nobody's going to ever get one of these in their car.
    • That's usually how it goes too. Repeat drunk drivers will probably get one of these, or one of the other drunk-driving prevetion devices. Nothing but a good thing, I say.
    • I see this as maybe needed for the few repeat offenders, and not the general population. It is a little extreme, and might be best applicable for those extreme cases where the idiot just doesnt learn.

      It could also be available, like the portable keychain analyzers, to people who would like to know themselves. I know I dont trust my judgement all the time when I'm drunk, but its too late when I wake up with her!!!
    • ...It seems to me short of a court order...

      Anyone convicted of a DUI or known to be a alcoholic could be ordered to install this in their car and be prohibited from driving any car without it. Those who don't drink and/or drive would not have to pay for such a system. If such a person drives a car without such a system, they would never drive again legally.
  • Common Sense (Score:3, Insightful)

    by BalorTFL ( 766196 ) on Monday May 30, 2005 @05:47PM (#12678761)
    "I'm not sure the auto industry is prepared to accept that for cost reasons," he said. "Neither will the driving public because the majority of them don't drink and drive. We're not there yet."

    This is -exactly- why we have government-mandated safety equipment. Think of it as a safety device mounted not just in your car, but outside it as well --- every one of these devices is another potential drunk driver kept off the road.
    • No, not really. If mandated, this device would only provide a false sense of security, like many of our silly laws.

      People who drive fucked up will find ways to drive fucked up. Mandating devices like this is merely treating a symptom; it is not a cure.
    • There is a simple measure of whether such things make sense. (Note that passing it isn't sufficient, only neccessary.) Assume that this invention would drive drunk driving rates to zero (it won't, but play along.) Is the value of the damage caused by drunk drivers currently greater than $600 * the number of cars manufactured or imported into the US? I have no idea, but I strongly doubt it. Add in the fact that it won't reduce DD rates to zero, there will be additional costs on inspections, fines for having
  • Hooray! (Score:5, Insightful)

    by Illserve ( 56215 ) on Monday May 30, 2005 @05:47PM (#12678764)
    One more thing to break preventing my car from working and leaving me sober and stranded in the middle of nowhere, with a broken part that's only available from the dealer thereby leaving my car unrepairable by the local garage off the freeway in Idaho.

    As the number of gadgets that have to function correctly for cars to run increases, the probability of getting from point A to B decreases to zero.
    • wow man, doomsayer extereme!

      All that doom and gloom, OR they could be pretty standard, universal, very reliable, available in most places... do you feel that your air bags break down all the time and set off sensors, etc?

      yes, i realize this is applicable to the ignition system, but so are alot of things that work jsut about every day just fine.
      • by Anonymous Coward
        Like hell these'll be "standard, universal, very reliable, available in most places".

        Well, ok, maybe they will be. Just like your catalytic converter. Did you know that its illegal for you to personally change your catalytic convertor or any other part of your engine that deals with exhaust quality control? EPA says it has to be done by a trained and certified professional. Not that anyone enforces the regulations.

        Anyway, that rule just keeps idiots who don't know what they're doing from spewing foul
      • I think you're missing something. First off, you mention air bags, etc. Are these things that should be mandated, or just a good idea? I like having seat belts, but I don't completely like air bags. I would still get both if they were options, because I like being alive and the potential air bag failure is acceptable to me. I should just have the option of not getting them.

        Forcing cars to have a sensor system like this doesn't stop people from drinking and it doesn't stop people from getting around th
      • What you apparently don't know, because you apparently don't commonly work on automotive electrical systems, is that many cars already have designs that cause this. For example, those cars with "smart" keys: The GM system will not allow you to replace the key reading unit without using the factory scan tool. If the unit is lost, and a certain number of attempts are made to install a new one without being performed correctly, you must actually replace the PCM.

        Also, these units will not be universal or, I s

    • Dude, sober up. ;)
    • Re:Hooray! (Score:3, Insightful)

      by NanoGator ( 522640 )
      "One more thing to break preventing my car from working and leaving me sober and stranded in the middle of nowhere, with a broken part that's only available from the dealer thereby leaving my car unrepairable by the local garage off the freeway in Idaho."

      I'm going to laugh if you have a car alarm, especially if you've never had trouble with it.
  • Interesting... (Score:3, Interesting)

    by FireballX301 ( 766274 ) on Monday May 30, 2005 @05:48PM (#12678768) Journal
    ..but there's already something out for people that got a DUI, it basically forces you to take a breathalyzer test before your engine starts. Google won't spit out a proper link though, so if someone could give me the link...

    It'd probably be much cheaper than $600 a car.
  • I live in Minnesota. It's damn cold here in the winter so everyone wears gloves. Obviously the inventor has never tried touching a stearing wheen with bare hands when it's 5 degrees below zero (F) outside.
    • Looking at your spelling, I'd say you just did touch a -5(-20c) steering wheel. That, or you need one of these devices.
  • sigh. (Score:2, Insightful)

    by grub ( 11606 )

    after his then-teenage son crashed into a utility pole while driving drunk and suffered minor brain damage

    A technical solution to a behavioural problem... yeah, those always work.
    • Well, until you find a way to stop people from choosing to be total fucktards, I'll live with a technology that could at least reduce the problem.
  • Questions (Score:2, Interesting)

    People raise good questions, how will they make sure it is the person who really is driving. What kind of tolerance does this have?

    Now for my opinion, I am in high school, probably the age group this is intended to protect. First of all what is the point in installing a 600 dollar sensor in a 300 dollar car. Also there are probably hundreds of thousands if not millions high schoolers who can drive. Most of them are safe drivers, who don't drink and driver but it is that small number who give the rest a bad

  • by Niban ( 227391 ) on Monday May 30, 2005 @05:55PM (#12678826)
    I can't be the only person who immediately contemplated swabbing their friends steering wheels with rubbing alcohol.

    No driving for you. ONE YEAR!
  • Gloves.
    • one word... Gloves

      You should have posted anonymously, now you are bound to be hunted down and jailed for 20+ years for violation of the DMCA and being un-american.
  • Oh, great. (Score:2, Informative)

    Another invention for the some do-goodnik politician to make mandatory on our vehicles. As if they aren't expensive enough already.

    The 1927 model 'T' Ford cost $3138.49 in 2005 dollars. Ponder that for a bit.

    • Perhaps you should ponder the concept of "inflation" a bit. To help you out, try reading this [jitterbuzz.com]. Using the CPI base multiplier of 10, that car would cost, in today's dollars, $31384.90. Of course, in the article, they claim this may drastically low-ball the value, and at the high end, a multiplier of something like 32.4 might be more reasonable, meaning Henry Ford's Model T might cost nearly $100,000 today.

      • Re:Oh, great. (Score:2, Informative)

        by gonknet ( 594078 ) *
        The Model T sold for $825 in 1908 when it was first sold to the public.

        The Model T sold for $575 in 1912. According to Forbes magazine: "When it sold for $575 in 1912, the Model T for the first time cost less than the prevailing average annual wage in the United States." ( link [wiley.com])

        Using the CPI:
        $825 in 1908 would cost $16327.82 in 2005
        $575 in 1912 would cost $11383.77 in 2005
        (link [westegg.com])

        The buying power of the average American family is much greater than it is today. There is no real good way to bring t
      • Check again. He said 'in 2005 dollars', meaning adjusted for inflation. In any case, IMO, and as your source seems to suggest, it's next to impossible to get an accurate read on prices from that far back. How can you compare a basket of goods in 1932 to a basket of goods in 2005?

        In particular, cars, computers, etc. can't be compared, because what passed for a car or computer in 1932 doesn't exactly relate to what passes for cars and computers now (didn't they have electric typewriters that could do basi

      • And in response to both replies to my post... *sigh* Me fail English, apparently...
      • Amm... No. People used to make $5 a -day- at a Ford factory floor (low level employees), and the car cost $295. Now, how much is that in today's dollars?
  • ...would be a device that tested whether you were over the limit but didn't affect the operation of your car.

    Think about it: how many adults are going to pay $600 for something that restricts the use of their car, good idea or not? But I'd personally pay that much for something that TELLS ME if I'm about to break the law.

    Such a device would be a powerful educational tool for people--they'd actually learn what .08 means in terms of their subjective experience! A lot of people have several drinks and t

  • The patent text shows that the inventor thought of gloves. One embodiement has the user wearing gloves with sensors, another the steering wheel needs periodic contact for the engine to keep running. US Patent Text from uspto.org [uspto.gov]
  • 420 ? (Score:2, Interesting)

    by rajinder ( 303281 )
    what happens when it's not alcohol?
  • So, in order to circumvent:

    Steering wheel version: Wear some gloves
    Glove version: Don't wear gloves
  • by pg110404 ( 836120 ) on Monday May 30, 2005 @06:26PM (#12679014)
    TFA doesn't exactly say how it works, but would it be possible to fool the sensor by wearing gloves or using some hand lotion or something?

    If the sensor works by checking the pH of the skin, a lot of things could throw it off (false positives/false negatives). If it works by checking the galvanic properties of the skin, would sweat or lack of sweat not throw it off? If it is looking for a specific molecular signature, wouldn't a good scrubbing of the hands with soap and water just before starting the car not get rid of it?

    If all these issues are foolproof, there is still the factor of the alcohol permeating the skin. I'd assume it would take a little while for the alcohol (which has a fairly low boiling point btw, so how much of it would remain on the skin at any given time) to work its way through the dermis and then through the epidermis.

    I'm not certain all legally intoxicated drivers would have enough alcohol on their skin to trip the sensor, but perhaps those who could barely stand could be better served with a simple reflex test (get the driver to push and hold one button, wait random amount of time, turn on a light, calculate how much time it takes the person to let go of that button and push a separate button, repeat 10 or 20 times, compute an average and compare it with that driver's norm).

    The 'blow in the tube' type checks the alcohol being expelled from your lungs. Since it checks the blood/alcohol level, it's a direct path from the blood to your breath through the lungs and is hard to fool. I don't know how well this through the skin version could realistically work.
  • This wheel is in no way compareable to a seatbelt. It's more comparable to a catalytic converter or an O2 sensor.

    The breathalyzer-style in car test is targeted at people convicted of a DUI. Thus, it has a very small target population. As soon as something similar occurs on all consumer vehicles, modifications to remove the wheel without consequence will pop up for those who want it. You can replace the emissions equippment on a car with commonly available kits. Your car PCU and the happy folks at the in
  • by syntap ( 242090 ) on Monday May 30, 2005 @06:58PM (#12679255)
    I think there should be passenger-side gloves that the girl has to put on to make sure you aren't taking the wrong one home, and to not let you out of the parking lot until she leaves.
  • The article seems to imply that this tool should be useful to prevent someone from driving, and maybe rental car companies and the like would go for something like that. On the whole, though, it seems unlikely that anyone intent on actually driving the car won't be able to fool it. Unless it's forced on them by an overbearing government, it seems the people who this might prevent from driving are unlikely to have it installed in the first place.

    I think that this sort of tool would be much more usefu

  • ... people to drive on the edge of the legal limit?

    Stupidest idea ever.
  • by wowbagger ( 69688 ) on Monday May 30, 2005 @07:39PM (#12679529) Homepage Journal
    The fundamental problem with this sort of a device is not technical.

    Assume for the moment you could build a device that could accurately read the driver's impairment level from any source - alcohol, drugs, sleep deprivation, cell phone, nudie magazine, screaming kids in the back seat, whatever. Assume for the moment this device is failure proof, fool proof, and cannot be misled.

    Now, there are two primary use cases for this device:
    1. The person requiring its purchase is the person who will be checked by it.

      In this case, the person it will be checking has proven they are willing to accept responsibility for their actions, and so the need for the device is fairly minimal - such a person is likely already going to limit their driving if they have been chemically altered, and all this device is going to do is allow them to drive when the are a little altered, as they will not have to leave the "safety margin" they otherwise would have left.
    2. The person requiring its purchase is planning on it checking somebody else.

      In this case, you open up the whole barrel of worms of legal rights, but most importantly the person being checked will either be
      1. a responsible person (as above) in which case, again, this device will just allow them to push closer to the limit, or
      2. they will be an irresponsible person, and thus will be highly motivated to disable the device, as it is forcing them to suffer the consequences of their actions.

God help those who do not help themselves. -- Wilson Mizner