# Driving while on Pot **URL:** \ **Category:** Factual Questions\ **Created:** [February 1, 2006, 4:29am UTC](https://boards.straightdope.com/t/driving-while-on-pot/342471 "2006-02-01T04:29:46Z")\ **Posts on this page:** 20\ **Page:** 2
**Author:** ![Beadalin](https://avatars.discourse-cdn.com/v4/letter/b/3be4f8/32.png) [@Beadalin](https://boards.straightdope.com/u/Beadalin)\ **Post date:** [February 1, 2006, 5:49pm UTC](https://boards.straightdope.com/t/driving-while-on-pot/342471/21 "2006-02-01T17:49:08Z")
Geez, it’s like I posted high. Sorry for all the spelling errors in my previous post. > [@](#): > > _Originally posted by **Q.E.D.** :_ > This depends on exactly what was tested for. That’s a good point, and I wish that I had made that distinction in the video I linked to (and I wonder if the distinction was made in the case **Lissa** mentions). ---
**Author:** ![II\_Gyan\_II](https://avatars.discourse-cdn.com/v4/letter/i/bbe5ce/32.png) [@II\_Gyan\_II](https://boards.straightdope.com/u/II_Gyan_II)\ **Post date:** [February 1, 2006, 6:46pm UTC](https://boards.straightdope.com/t/driving-while-on-pot/342471/22 "2006-02-01T18:46:31Z")
> [@Q.E.D.](#): > > It’s metabolized out of the bloodstream fairly quickly; ~3 hours or so. So, if they were testing for THC, it can be definitively concluded that the driver had smoked shortly before the accident From [Pharmacokinetics of cannabinoids](http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=16237477&query_hl=1&itool=pubmed_docsum): > [@](#): > > THC is eliminated from plasma in a multiphasic manner, with low amounts detectable for over one week after dosing. and [Temporal indication of marijuana use…](http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=11599597&query_hl=1&itool=pubmed_docsum) > [@](#): > > Urinary concentrations of THC greater than 1.5 ng/mL suggests marijuana use during the previous 8-h time period. Now, the French study you quoted, which I remembering reading earlier, assigned ‘marijuana use’ to plasma levels above 1ng/ml. Question is what does 1ng/ml plasma correspond to in urinary concentration and what does “low amounts” in the first paper mean? ---
**Author:** ![Queuing](https://avatars.discourse-cdn.com/v4/letter/q/90ced4/32.png) [@Queuing](https://boards.straightdope.com/u/Queuing)\ **Post date:** [February 1, 2006, 6:49pm UTC](https://boards.straightdope.com/t/driving-while-on-pot/342471/23 "2006-02-01T18:49:12Z")
I have driven both drunk and high on pot. Driving drunk was a very bad idea. I did it once, I was bouncing off curbs going around corners, I knew that was I was doing was dangerous and unsafe but because I was drunk I didn’t much care. KInd of like the the time I mouthed off to the 6’6 275 pound guy at the bar. I have driven high to many times to count. Hell I have smoked a joint while driving to mnay times to count. While I wouldn’t say I was as good a driver when sober, I did not think I was at all dangerous. I found myself driving slower (like the speed limit which when sober I never do), however a consistent speed was harder to achieve. Reaction wise no problem. One time on the 401 (major CDN highway) a car swerved and smashed into a car in front of me. I was easily able to avoid the accident. Another time a truck wheel fell off a transport truck in front of me (remember when that seemed to be happening every week in the GTA?), and I calmly avoided it. So in my experience driving skills go like this: Sober \> Pot \> drunk (but no way should the 3rd even be in here, IMO no comparison to weed and alcohol when it comes to driving). ---
**Author:** ![CC](https://avatars.discourse-cdn.com/v4/letter/c/f1d935/32.png) [@CC](https://boards.straightdope.com/u/CC)\ **Post date:** [February 1, 2006, 7:06pm UTC](https://boards.straightdope.com/t/driving-while-on-pot/342471/24 "2006-02-01T19:06:16Z")
Again, I support the anecdotal evidence that caution and compensation appear to be the significant hallmarks of marijuana intoxication when someone is driving, as opposed to the clearly dangerous belligerance and false bravery of the alcohol impaired driver. However, it is not without its own drawbacks. A friend was driving while stoned and began slowing down and came to a nice, tidy halt in the middle of a block one night. When I asked him why, he told me it was because of the stop light, which at that point was probably about 200 feet still in front of us. He was just being cautious, of course, and thankfully, there were no cars behind us. I encouraged him to keep driving until we got a little closer and he would have to actually stop because we would be right there where we would be expected to stop if the light were still red when we got there. I’ve bee driving under similar circumstances and have found myself crawling along - just to be safe - and have had to speed up and have worried that in my condition, maybe I shouldn’t be driving and I’ve worried so much that I start slowing down again. It is definitely best to be clean and sober when operating heavy machinery in the midst of society, but I’ll take my chances on the road with mellow, overyly cautious stoners to cock-sure, aggressive drunks any day. xo, C. ---
**Author:** ![panamajack](https://avatars.discourse-cdn.com/v4/letter/p/47e85d/32.png) [@panamajack](https://boards.straightdope.com/u/panamajack)\ **Post date:** [February 1, 2006, 7:11pm UTC](https://boards.straightdope.com/t/driving-while-on-pot/342471/25 "2006-02-01T19:11:19Z")
I’m not quite sure I buy the argument – if even while stoned you know you’re impaired and have to compensate, wouldn’t you be better off not driving at all? Even if you are doing better than the drunk driver, it’s not like it’s a competition. I have witnessed at least one case where driving while high was dangerous : We saw four kids smoking in a car. Then they passed the pipe to the driver, and _he re-lit it_. Even at one point asking someone in the back for something (a lighter, I think). So if you’re going to drive while high, at least have a friend around to light it up for you. ---
**Author:** ![Clothahump](https://avatars.discourse-cdn.com/v4/letter/c/51bf81/32.png) [@Clothahump](https://boards.straightdope.com/u/Clothahump)\ **Post date:** [February 1, 2006, 7:37pm UTC](https://boards.straightdope.com/t/driving-while-on-pot/342471/26 "2006-02-01T19:37:31Z")
When I was a cop, I worked way too many wrecks with way too many people killed or injured because some jerk felt that he needed to drink or toke up before he got behind the wheel. Driving impaired - from any source: booze, pot, pills, whatever - should be a felony with mandatory prison time. If you are driving impaired and injure someone, you should be tried for attempted murder, and if you kill someone, you should be tried for murder. Not this halfass “vehicular manslaughter” crap that allows impaired drivers to kill others and get a slap on the wrist for it. ---
**Author:** ![II\_Gyan\_II](https://avatars.discourse-cdn.com/v4/letter/i/bbe5ce/32.png) [@II\_Gyan\_II](https://boards.straightdope.com/u/II_Gyan_II)\ **Post date:** [February 1, 2006, 7:38pm UTC](https://boards.straightdope.com/t/driving-while-on-pot/342471/27 "2006-02-01T19:38:20Z")
> [@panamajack](#): > > So if you’re going to drive while high, at least have a friend around to light it up for you. Driving while high is different than driving while _getting_ high. ---
**Author:** ![pablo2006](https://avatars.discourse-cdn.com/v4/letter/p/3da27b/32.png) [@pablo2006](https://boards.straightdope.com/u/pablo2006)\ **Post date:** [February 1, 2006, 7:44pm UTC](https://boards.straightdope.com/t/driving-while-on-pot/342471/28 "2006-02-01T19:44:12Z")
I think driving high is a very bad idea. If it can make you spend 20 minutes looking for your keys or walk into a room without remembering what you were after then it’d be just as easy to forget to check a blind spot, etc. ---
**Author:** ![Lissa](https://avatars.discourse-cdn.com/v4/letter/l/85f322/32.png) [@Lissa](https://boards.straightdope.com/u/Lissa)\ **Post date:** [February 1, 2006, 7:52pm UTC](https://boards.straightdope.com/t/driving-while-on-pot/342471/29 "2006-02-01T19:52:56Z")
> [@pablo2006](#): > > I think driving high is a very bad idea. If it can make you spend 20 minutes looking for your keys or walk into a room without remembering what you were after then it’d be just as easy to forget to check a blind spot, etc. Dude, I do that completely _sober._ ---
**Author:** ![pablo2006](https://avatars.discourse-cdn.com/v4/letter/p/3da27b/32.png) [@pablo2006](https://boards.straightdope.com/u/pablo2006)\ **Post date:** [February 1, 2006, 8:02pm UTC](https://boards.straightdope.com/t/driving-while-on-pot/342471/30 "2006-02-01T20:02:44Z")
Lissa, don’t get me going on women drivers. :Þ j/k ---
**Author:** ![treis](https://avatars.discourse-cdn.com/v4/letter/t/bc79bd/32.png) [@treis](https://boards.straightdope.com/u/treis)\ **Post date:** [February 1, 2006, 8:32pm UTC](https://boards.straightdope.com/t/driving-while-on-pot/342471/31 "2006-02-01T20:32:40Z")
> [@Q.E.D.](#): > > At least [one](http://webcenter.health.webmd.netscape.com/content/article/115/111967.htm) [study](http://www.newscientist.com/channel/mech-tech/motoring-tech/dn8407) suggests that stoned drivers are twice as likely as sober drivers to be involved in a fatal car accident. Though not nearly as dangerous as alcohol, it’s still by no means a safe state in which to be driving, if the finding of this study are accurate. Any study that groups Pot and Alcohol under results for Pot, which this one apparently did, has to be questioned. ---
**Author:** ![XaMcQ](https://avatars.discourse-cdn.com/v4/letter/x/f9ae1b/32.png) [@XaMcQ](https://boards.straightdope.com/u/XaMcQ)\ **Post date:** [February 1, 2006, 8:56pm UTC](https://boards.straightdope.com/t/driving-while-on-pot/342471/32 "2006-02-01T20:56:51Z")
> [@AHunter3](#): > > Naah. I’ve done all three. I’m safer by quantum leaps on both skill and judgment on acid than on alcohol, and to a lesser extent more so than on pot. I’m more patient and more relaxed than when sober, but large-picture judgments (planning, keeping mind on going to Cincinnati and not Cabo San Lucas) are more questionable. Either you are a very strange person(and I have known one screwball individual who would trip and go talk to authority figures, do important business, drive, talk to cops, etc. and seem perfectly lucid) or you are just not experiencing the kind of brain-melting affects I remember. The one time I did this (not on purpose; I was _promised_ it would take at least an hour to have any affect) I thought I was going to kill us all. I had a great deal of trouble judging distance, time, or even whether cars around me were going forward or backwards. I was incredibly distracted by flashing lights, tracers and halucinations, and too paranoid to pull over lest someone stop and ask what was wrong. Patient and relaxed are not what I associate with LSD, ever. Half the time it had so much speed and strychnine(I’ve read it may not really be strychnine, but that is what we always though it was when it was causing the teeth-clenching, the cramps and the nausea) that I wanted to climb the walls. As for keeping my mind on things, heh. I might be able to sit in one spot and stare at that lava lamp or string beads by blacklight for hours, I don’t think that’s an idea driving state of mind. I recall on more than one occassion losing the ability to speak or understand English. **DO NOT DRIVE ON LSD!** ---
**Author:** ![Q.E.D](https://avatars.discourse-cdn.com/v4/letter/q/51bf81/32.png) [@Q.E.D](https://boards.straightdope.com/u/Q.E.D)\ **Post date:** [February 1, 2006, 9:02pm UTC](https://boards.straightdope.com/t/driving-while-on-pot/342471/33 "2006-02-01T21:02:25Z")
> [@treis](#): > > Any study that groups Pot and Alcohol under results for Pot, which this one apparently did, has to be questioned. If you are referring to this part > [@](#): > > Using cannabis and alcohol together was 16 times more risky than driving with neither drug in their body. It’s just another statistic culled from the research. There’s nothing questionable about it. ---
**Author:** ![Carnac\_the\_Magnificent](https://avatars.discourse-cdn.com/v4/letter/c/ccd318/32.png) [@Carnac\_the\_Magnificent](https://boards.straightdope.com/u/Carnac_the_Magnificent)\ **Post date:** [February 1, 2006, 9:29pm UTC](https://boards.straightdope.com/t/driving-while-on-pot/342471/34 "2006-02-01T21:29:54Z")
> [@Beadalin](#): > > There’s a video on MSN right now about pot’s effect on driving (shot in the UK). > > [You can watch it here.](http://video.msn.com/v/us/v.htm?g=75ece25e-b315-45da-9ca7-304567beed18&f=msnhome) > > They admit this is in no way scientific, but they have a guy take a driving test, then smoke up and take the test again. He performed better stoned than he did sober. You’re right. It’s in no way scientific, so why offer it as such? The methodological problems are many, the validity nil. ---
**Author:** ![Beadalin](https://avatars.discourse-cdn.com/v4/letter/b/3be4f8/32.png) [@Beadalin](https://boards.straightdope.com/u/Beadalin)\ **Post date:** [February 1, 2006, 10:07pm UTC](https://boards.straightdope.com/t/driving-while-on-pot/342471/35 "2006-02-01T22:07:24Z")
> [@](#): > > It’s in no way scientific, so why offer it as such? I don’t think I did, and neither did the video. It’s anecdotal, much as the rest of this thread is anecdotal. But in the absence of much scientific study, that’s about all we’ve got. Moreover, in the US, government-sanctioned studies rely on driving simulators rather than the real thing, which could impact results. They also rely on pot grown by the government, which is not necessarily comparable to pot purchased on the street. And further, pot purchased on the street varies greatly in its potency, anyway. All of which makes what scientific data that exist somewhat suspect, in my view. YMMV (mileage not accumulated under the influence of marijuana, of course). ---
**Author:** ![Bomzaway](https://avatars.discourse-cdn.com/v4/letter/b/e480ec/32.png) [@Bomzaway](https://boards.straightdope.com/u/Bomzaway)\ **Post date:** [February 1, 2006, 10:50pm UTC](https://boards.straightdope.com/t/driving-while-on-pot/342471/36 "2006-02-01T22:50:12Z")
Personally, (I light up now and then BTW) I can’t stand driving stoned! I mean, why even get high if you have to get behind the wheel and act all responsibly? It’s not that I can’t drive stoned, I certainly can and have many times, but it just plain sucks to do. Especially right after smoking, at the peak of potency. After about 45 minutes or so, then yeah, no big deal, but I’d rather get to where I’m going before lighting up. Actually before I get to where I’m going, I’ll stop and get some twinkies. Oh, and a 2 liter bottle of Mr Pibb… …and some of those Oreo cookies with the chocolate coating…and Captain crunch…with some 2%…and strawberries (YEAH, I love strawberries!)…and those candies that look like buckets of paint and you stick the brush in and lick it…yeah, those are great…and some water for the cottonmouth…gotta have water…oh, and twinkies! Oh wait, did I say twinkies already? ---
**Author:** ![Carnac\_the\_Magnificent](https://avatars.discourse-cdn.com/v4/letter/c/ccd318/32.png) [@Carnac\_the\_Magnificent](https://boards.straightdope.com/u/Carnac_the_Magnificent)\ **Post date:** [February 2, 2006, 1:45am UTC](https://boards.straightdope.com/t/driving-while-on-pot/342471/37 "2006-02-02T01:45:06Z")
> [@Beadalin](#): > > I don’t think I did, and neither did the video. It’s anecdotal, much as the rest of this thread is anecdotal. But in the absence of much scientific study, that’s about all we’ve got. Actually, I was referring to MSN. 😉 ---
**Author:** ![neutron\_star](https://avatars.discourse-cdn.com/v4/letter/n/51bf81/32.png) [@neutron\_star](https://boards.straightdope.com/u/neutron_star)\ **Post date:** [February 2, 2006, 6:07am UTC](https://boards.straightdope.com/t/driving-while-on-pot/342471/38 "2006-02-02T06:07:17Z")
I come bearing cites. From [the conclusion of a U.S. Department of Transportation study](http://www.nhtsa.dot.gov/people/injury/research/COMPEND2.HTM): > [@](#): > > Volunteer subjects participated in several sessions in which they were dosed on alcohol, marijuana, or a placebo, then drove motor vehicles in various controlled on-road traffic situations (e.g., closed interstate highway). Dual-controlled vehicles were used, and a researcher was always along to take control if warranted. Marijuana was found to have a performance impairment effect equivalent to an alcohol blood alcohol concentration (BAC) level between .04 and .08 only in lane maintenance performance measures. From [the UK’s Department for Transportation](http://www.dft.gov.uk/stellent/groups/dft_rdsafety/documents/page/dft_rdsafety_504567.hcsp): > [@](#): > > Both simulation and road trials generally find that driving behaviour shortly after consumption of larger doses of cannabis results in (i) a more cautious driving style; (ii) increased variability in lane position (and headway); and (iii) longer decision times. Whereas these results indicate a ‘change’ from normal conditions, they do not necessarily reflect ‘impairment’ in terms of performance effectiveness since few studies report increased accident risk. [Here](http://www.sciencedaily.com/releases/1999/03/990325110700.htm) is a story about a University of Toronto meta-analysis that combed through numerous studies on the effect of marijuana on driving, along with accident reports from the U.S. and Australia, and came to the conclusion that marijuana’s effects on driving were negligible. I have more cites if anyone wants them, but they pretty much come to the same conclusion: marijuana does have a measurable negative impact on SDLP (stanard deviation of lateral position), but very little or no effect in other categories. Accident studies, however, do not reflect said impact, suggesting that marijuana smokers adequately compensate for their state. Studies employing proper methodology consistently show that marijuana has less of a negative impact on driving than sleep deprivation, old age, cell phone use, and many prescription drugs. ---
**Author:** ![CC](https://avatars.discourse-cdn.com/v4/letter/c/f1d935/32.png) [@CC](https://boards.straightdope.com/u/CC)\ **Post date:** [February 4, 2006, 7:29pm UTC](https://boards.straightdope.com/t/driving-while-on-pot/342471/39 "2006-02-04T19:29:18Z")
This just in from News of The Weird by Chuck Shepard, carried in the _Chicago Reader_, and probably lots of other places: “Writing in the\* British Medical Journal\* in December, researcher Jean-Louis Martin of the Universite Claude Bernard in Lyons, France, reported that French motorists driving under the influence of marijuana were nearly twice as likely to be involved in a fatal accident as drivers who hadn’t used the drug. Less prominently noted in the article (and consequently in news reports about it) was that though French drivers are just as likely to use marijuana as alcohol, alcohol accounted for more than 11 times as many fatal crashes.” xo, C. ---
**Author:** ![Q.E.D](https://avatars.discourse-cdn.com/v4/letter/q/51bf81/32.png) [@Q.E.D](https://boards.straightdope.com/u/Q.E.D)\ **Post date:** [February 4, 2006, 7:38pm UTC](https://boards.straightdope.com/t/driving-while-on-pot/342471/40 "2006-02-04T19:38:34Z")
**CC** , that’s the study I referred to in my post #7 above. [Previous page](https://boards.straightdope.com/t/driving-while-on-pot/342471.md?page=1) [Next page](https://boards.straightdope.com/t/driving-while-on-pot/342471.md?page=3)