Scientists have built a high-tech simulator to lay this important question to rest

In the Simulator Dani Machlis

When I slipped behind the wheel of the traffic simulator at Israel's Ben Gurion University recently, it was less than two minutes before I was bumping into the virtual cars and swerving around pedestrians. Maneuvering through the tree-lined urban roads projected in dayglo colors on giant screens was tricky--and I wasn't even one of their hard-drinking or toking research subjects.

Professors David Shinar and Adi Ronen at the university's Laboratory for Human Factors in Road Safety just opened the custom-built driving simulator this spring where they will conduct further research on pot-smoking drivers versus their inebriated counterparts. The gleaming bronze GM Cadillac simulator, which faces a wall of synchronized 160-degree screen images, immerses drivers in a personalized road trip like an IMAX movie, while researchers monitor their glance, expression, and heartbeat. Anyone who has sped home after a night drinking at the bar, or gone out for a lazy ride after smoking marijuana, may already know intuitively what two Israeli professors have been driven to discover.

In a recent preliminary study, the professors enlisted 14 students -- all recreational marijuana users -- and tested them both when they were stoned and when they were soused. (Recruiting subjects for the marijuana and alcohol studies doesn't require much work. The lab doesn't even advertise, but as soon as word of the study got out, volunteers came rushing in.) The students were tested for physiological strain and driving performance as they drove through rural communities and desert scenes, and past roadblocks and pedestrians. One group smoked low and high doses of THC. Another downed vodka and "orange drink" cocktails to reach Israel's legal limit of .05 percent blood alcohol content. Others took a placebo.

None of the doped-up or drinking drivers were models of safety on the road. They tended to switch lane positions, swerve, and vary their steering. But the THC cigarette smokers drove significantly slower than the liquored-up subjects, who zoomed down the virtual lanes. The drinking drivers also tended to be confident and boast a sense of control, while the pot smokers seem to be "more aware of their impairment."

But that feeling can be a road hazard. "People who smoke marijuana think they can compensate for the drug's effect, but they can't," said Shinar, who founded the lab and is the chief scientist of Israel's National Road Safety Authority. "A detachment from reality is dangerous." More people die in traffic accidents than in wars, Shinar emphasized; he hopes this study will step up enforcement of dosed-up drivers.

What's the next stop on the research track? Results from a study on how double-dosing on pot and booze impacts driving patterns. The lab will also test the effects of marijuana and fatigue on "hazard perception," and how caffeine-packed energy drinks, when mixed with alcohol, alter driving behavior.

But teetotal drivers aren't off the hook. Researchers also want to rev up the simulator to see whether talking on cell phones and with other passengers make sober drivers dangerous behind the wheel.

Driving Simulator:  Dani Machlis

Want to keep track of the latest concept cars, automotive innovations, and more? Subscribe to Popular Science today, for less than $1 per issue!

30 Comments

It’s an interesting writeup of an interesting study, and the results are probably valid to some degree, but one potentially confounding factor not mentioned is the effects of the difference between driving a car and driving a simulator.

Simulators of the type described are of great value in a wide array of research into the driver-vehicle-road system, but no matter how realistic the wraparound imagery and operation of the car controls, the lack of actual motion sends conflicting signals to the brain: eyes say you’re moving, rest of senses say you’re stationary. This sensory disagreement tends to cause discomfort (simulation sickness — also observable in some players of certain video games) that can involve dizziness, nausea, and general unease. It also causes cognitive and physical confusion; one tends to second-guess control inputs because the response doesn’t feel right. The task load is increased, because the conscious mind is tagging along “cleaning up” after this subconscious tendency to second-guess. The degree of disparity between performance in an actual vehicle and in a simulator varies by individual and by individuals’ experience with simulators, just as some people easily get seasick and others don’t, and many people initially very prone to seasickness become much less so with prolonged, repeated experience. Also like seasickness, awareness of the potential and conscious will against it is largely ineffective. I recall the astonished and frustrated reactions of many of us in a sizeable group of experienced, knowledgeable traffic safety researchers upon trying the very sophisticated driving simulator at the University of Iowa’s Operator Performance Laboratory some years ago during a symposium — even those who scoffed at the errors others were making made those same errors when their turns in the simulator came.

The relevance here should be fairly obvious: the subjects of this present study probably had little or no prior experience with driving simulators, so were likely to exhibit significant simulator-induced driving impairment and simulator sickness. And we probably don’t know the degree to which alcohol and cannabis attenuate or amplify either or both effects. So the difference between drunk and stoned drivers may be greater or lesser than the study found, and it may or may not be qualitatively different than the study found.

lol!

Nice story!

I like the point that you're more dangerous when you overestimate your capacity, like drunk people do, but stoned people don't. Unless they think they are God.

But I wouldn't underestimate the danger of driving stoned. I remember once almost killing a car full of friends when I was stoned and almost went through a red light onto a 4 lane highway. But then I didn't. As best I recall.

Exccellent story, Jessica!

Dr. Stern is absolutely correct. If you were to put someone behind the wheel of their Honda that they have been driving for many years, you would get a much better result than if you were to throw them into a video game / simulator for the first time. Obviuosly, it is legally imposible and morally wrong to conduct a real life test. What is important is that you understand that approximately 32% of all traffic fatilities are due to drunk driving. Dude!

I smoke regularly...

I have run a red light, the day i got my new bong too. It was a heart pumping experience and scared the crap out of me! But I was not high. After getting high 15 minutes later and continuing my 45 minute drive home I was feeling a lot for observant, cautious and aware especially after speeding through a red light in the middle of downtown.

I was just excited after my purchase and wanting to try it out
(you know...)

I just feel safer when I'm driving high, i feel a lot more positive about my driving.

But about the article i bet the outcomes would be a lot different if they were on a real road and in a real driving environment.
s was said by the sober driver;
"Maneuvering through the tree-lined urban roads projected in dayglo colors on giant screens was tricky--and I wasn't even one of their hard-drinking or toking research subjects."

Many years ago before I knew any better. I drove home stoned on pot after a party. I thought I was being so careful and felt I was doing a masterful job at driving.
The next morning there was a knock on the door by a police officer. I had parked on the wrong side of the road facing the wrong direction.
I was completely unaware that I had done so.
That was the last time I drove high.
Any idiot that thinks ANY sort of substance that alters your perception of reality is OK to use when driving should be locked up for the safety of others.
They don't call them "mind-altering" for nothing.
I'm not surprised at the results of the test.

This has been researched to death. The bottom line is that the impairment from pot rarely gets above the level of .08 blood alcohol level -- the lowest level of DUI for alcohol.

Road and Track did an article titled "Puff, the Dangerous Driver" in 1980. The purpose was the same as this research. They took two groups of people. One group got increasing doses of alchol while the other got increasing doses of pot. Then they made them drive a closed course.

The alcohol drinkers were quickly all over the road. The pot smokers just got better at the course with each new trial.

This is consistent with the US Federal Government's own research. In short, pot is not, and never has been a significant hazard on the road. There is just no evidence that it plays a major factor in any significant number of road accidents. IN fact, research done in Australia showed that, overall, pot smokers are probably better drivers than average -- meaning that they can effectively compensate for the effects.

Note that this applies to experienced pot smokers. Inexperienced pot smokers could be expected to suffer more impairment.

But, in any event, assuming that marijuana tested the same as alcohol, that would only mean that the laws should be the same as for alcohol. You will note that we don't make alcohol illegal to try to deal with the problem of drunk driving. We tried it once and it was a complete disaster. See, for example, http://druglibrary.org/prohibitionresults.htm

Anyone who wants to read the Federal research can find it at http://druglibrary.org/schaffer/index.htm under Drugs and Driving.

When can I put my kid through this test?

Who Drives Better: Drunks or Stoners?

It would have been nice if you would have answered the question.

I agree with Daniel Stern 100%. The study only observing who is having more fun in a virtual reality game.

First off, Its factual that Alcohol is more dangerous then Marijuana, especially from an impairment view.

Secondly Fourteen students is not nearly enough test subjects. Each Individual has there own Genetic Tolerance to Marijuana depending how long the bloodline has been using it. Five Generations in my family, so far.

I agree Alcohol boasts your confidence through the roof, and you might think you can drive... then again all that formaldehyde being made in your liver from that alcohol has not hit your brain yet... and when it does you just might be paralyzed for a short moment on the road.

I think the reason the answer is hidden is because you DONT want us driving stoned, because we might be Too Good at it. People that are not experienced driving high might want to try it and get hurt. That is a good reason, but not good enough to say people cant drive when there euphoric.

Being a regular user of cannabis, my own experience driving stoned is; drive efficient, correctly and responsibly. Always be aware of your surroundings. Its really hard to not drive excellent because my mind is racing a mile a minute, so much to think about, and because im stoned, and thinkin so epic fast everything else is slowing down, and I can judge my own actions and task them accordingly to my visual observation of the environment and calculate each variable like a big bright red stop sign. Do that when your drunk? Lol

In the US it's legal to get a prescription for a drug that will make you "Stoned". And drive.

You see the correct answer is that political lobbying and corporate pharmaceuticals make these decisions. Not scientists.

Great point, Daniel! To be extremely honest, I drove from Rumford, Maine. U.S.A. to New Haven, Connecticut. Stoned. My driving was obviously good enough to not stir up any suspicion amungst the Maine, New Hampshire, Massachusettes, Rhode Island and Connecticut state police. I do feel more relaxed while stoned, I pay much more attention, having ADHD as a 23 year old person, that goes a long way. But, every single living organism reacts differently to everything, so it is hard to judge one drug and it's effects on human beings and their ability to drive under the influence. I just know I am a relatively decent driver. But, of course, just like in the army, we did simulations like humvee driving, shooting in the middle of a gunfight in the streets of Baghdad, and having gone to Baghdad and tested my knowledge, I can definitely say, that first-hand, raw, real experience, is much different than anyone can 'teach/train' you on a silver screen.

Also, DarkFX, absolutely true! Excellent observation put into words!

Fellow toker tip of the day: General George Washington, U.S. Continental Army, also, the "first" (everyone knows that John Hanson ((November 5, 1781 until November 3, 1782.)) was the first president, also considering he was the first man ever to sign his name as the President of the Union), ('Cause George Washington was off fighting the British during that time). Anyways, to make a long story short and to not go into too much of America's young history, General George Washington also smoked pot. Was he a bad guy, did that supposed "Mind-Altering" drug hinder his ability to continue his legacy of the greatest general (on and off the battlefield, a genius with battlefield tactics, etc.) in the history of the United States Army? ...and later to become the one of the very few presidents that upheld the consitution of which this country was whole heartedly founded upon? ...was he a bad guy for toking up a time or two, or a few hundred? Hell 'motherfucking' no. My point settled.

As for you, Anitah, that's not the drug making you park the car on the other side of the road, that's just plain stupidity. With all due respect, of course. After driving on the 'right' side of the road, or whatever side you may drive on for so long, it really becomes more... what's the word...? ...habitual. Even those that are drunk, can, in-fact, drive and park their car on the correct side of the road, and I do apologize for my, abrupt rudeness, but, once again, much like any other 'mind-altering' drug, those who have no ancestory behind it, like generations of those before you, yet, still in your bloodline, it will effect you differently, than others who - one: smoke pot on a regular basis, and two: who actually have it literally 'in their geneology'. Again, my case rested, point hopefully taken.

In conclusion -- pot isn't as bad as the government-funded scientist in the early 1900s deemed it to be. Just, the government can't make a definite profit on any taxation as of yet, without stirring up the fears and concerns of Americans, and those mothers against that drunken driving problem that the vast majority of modern day americans have. But, thankfully, I'm sure Obama will eventually legalize it...considering to this day, pot is becoming more legal. In the state of Maine now, to have an ounce or less of marijuana, is classified as a class B misdemeanor...it's all a matter of time.

Again, watch the Movie 'Idiocracy', with Luke Wilson, it provides no valid argument, it's just pretty freakin' funny! HAHA!

The only way to answer the question correctly would be to survey people, find out what percentage of the population have driven drunk and/or stoned, and compare those numbers to the percentages of auto accidents or fatalities that have been reported for each group of "inhibited" people, then factor out a few from each situation for people that can't drive regardless of physical state.

Gerhard

In addition to Dan Stern's excellent points, I suspect thet tokers would be biased toward a favorable outcome for pot ... "see dad, I told you it wasn't as bad as drinking" ...

While they could not, likely, perform better that their impaired best (after smoking) they could reasonably be expected to care less about how well they did after drinking.

You cannot possibly be serious.

Any...scratch that: EVERY time you get behind the controls of any vehicle/craft/vessel/equipment, or WHATEVER, after having consumed drugs [whether legal or not] and/or alcohol you WILL INEVITABLY alter your perceptions, reflexes, and reactions/reaction-time. Spending government/university time and finances to determine whether you drive worse stoned or drunk?! Are you kidding?! Like it could ever matter! If a member of my family were injured/maimed/killed by anyone under the influence of anything stonger than coffee, I would think that people would be more interested/concerned about what I would do to that person than arguing the ramifications of if they had "ONLY" been stoned instead of drinking!!!

This study, and this article are a waste of the paper required to actually print them up!

GET OFF THE PHONE
LAY OFF THE GAS
PUT DOWN THE BOTTLE/JOINT
AND GET OFF MY @$$

Stop discussing the finer points of pot v. alcohol, and start paying attention to the task at hand, DRIVING!!!

Well, like I said, earlier. The point of my experience deems, that smoking pot, works for me. I'm not gonna' preech to the others that utilize this thread, however, being a combat veteran, in Iraq for 14 months, driving humvees as a job, part-time, as a .50 Cal. gunner, as a gunner, I constantly wached my flank, my six, hell, even my twelve, also, getting attacked, bombed, shot by tracer rounds, that, by god let me tell you, they haunt you every time you close your eyes, because all you can do is fire back, and wait for a burning sensation, 'cause boy that's where you're shot. Also, driving in a small-ass death box, with a bazillion pounds of gear, ammo, weapon, flak vest with 7.62 federal, NATO round-stopping ceramic plates, and side plates that serve the better purpose amungst the clammer, a helmet, full gear, 130+ (high, in the hottest day of the summer was 157 degrees) degrees inside that death box, with no AC, well, an AC setting, but the air intake takes in too much fine-sedimentary sand that gets into the smallest of crevices, makes the motor work much harder than needed, blowing out just hotter air, and being attacked in that death box is bad, 'cause you step on the gas pedal, and even using the better refined out of the two grades of diesel (JP-8 and DF-2), DF-2 being the higher octane grade, you only get a max speed of 55, 60 if at all lucky...

--you tend to get a bit anxious, and anxiety attacks do set in, and those, my friend, are extremely bad, your throat closes up, you get weezy, your blood pressure rises, your heart feels like it's going to push through your chest, you hyperventilate, you may go dizy, and eventually pass out, minor asphyxiation sets in, lack of oxygen to the brain, bad idea. Especially when I drive, people who get to close to my ass, set me off more than anything, defensive driver's training sets in, I get irritated, I get scared, paranoid, start thinking, then become parched for oxygen, so-to-speak. Pot, my friend, that helps me wonders. I calm down, pay attention, I am more relaxed, I also, believe it or not, I am a lot more polite, etc., so, I'm just explaining my experiences.

Before, in one of my...now four speeches, chemical compounds, such as THC, LSD, etc., reacts differently to every single organism on this earth, making it extremely difficult to test on many different people, pot should be legalized, mind you, but it should be enforced, just like alcohol is, 'cause cowboy, I hate to admit it haha, you're kinda' right.

This has been studied to death already. The conclusions always are that marijuana is simply not a significant hazard on the road. Government stats prove it, and all kinds of different studies prove it. The bottom line is that experienced pot users know what the effects are like and are able to easily compensate for them. Marijuana does not destroy coordination like alcohol does. Marijuana is more of a change in mood.

Road and Track did an article titled "Puff, the Dangerous Driver" back in 1980. The purpose was to show that alcohol and marijuana are both dangerous on the road. They took two groups of people. One group got increasing doses of alcohol. The other people got increasing doses of marijuana. After each new dose, they drove a closed course.

The alcohol drinkers were quickly all over the road. The marijuana smokers just got better at the course with each new run.

Those results are consistent with the results of every other piece of research on the issue. Bottom line, marijuana simply isn't involved in any great number of traffic accidents -- according to the Federal Government's own statistics. But that certainly won't stop the prohibitionists from looking for one more scary headline.

This is a garbage study if only for the methodology -- first there was no proper control done. Yes, I know they gave some of the students placebo instead of drink, but I don't think that this is good enough. The placebo effect is a very powerful one and probably suggested a level of inebriation in the students who received it. A proper control would be testing each student sober, drunk, stoned, and then sober again to (in order to rule out the effects of learning the course.)

Another troubling thing in the test is that they are comparing high dose THC to extremely low dose alcohol (.05% is barely over half of the legal limit in the States!). If they are going to try to say that marijuana is nearly as dangerous as alcohol, they need to test high level intoxication (.15%+) if they want the study to be taken seriously. This outcome of this study was clearly decided before the study was undertaken, which is the antithesis of real science. It is amazing that such sloppy methodology passes as science these days... thanks Mythbusters...

I'm so sick of drunk driving/stoner accidents, last year in my state a car of young men pulled out infront of a semi trailer while under the influence of pot and 3 out of four of them died. Several months ago my youngest brother in law hit a truck head on because he thought he had a green arrow to turn. (He didn't, and witnesses said he just drove right into the truck) He uses pot so regularly that it is always going to be in his system, luckily that time no one got seriously injured. It doesn't seem like a hard lesson to me. Mind altering drugs are going to affect my mind. As for needing to take it to drive... Just call a taxi or ride the bus, I don't want you driving while im out on the roads.

It is unfortunate that the driving accident has changed your perception on marijuana mindset through death, but the fact is a Gradient of Stupid and Smart people Exist whether they smoke marijuana or not, and driving accidents happen. Its about overall experience and common sense.

Stupid Sober drivers are Very Common. Stupid People that smoke marijuana make up a large quantity of us and project the "Idiotic" stereotype and will probably cause accidents regardless of influence.

When Smart people smoke marijuana there skills are usually considered unacceptable because an Intellectual Stoner is Rare. Or they are not even bothered with because they still have there common sense to drive the same (if not better), and you dont hear about them.

Its all about how you use it.

I occationally toke and I also drink.

I will not drink and drive if I think I'm anywhere near the legal limit because I know that alcohol effects me in a negative way. No one needs to tell me this.

That said, I have a 12 year clean driving record that shows I am a good driver, what it doesn't show is that perhaps 25% of the time I was actually stoned while driving.

Now, I am not stupid enough to drive after taking multiple bong hits (I don't smoke that much anyways), but I know for a FACT that after moderate consumption of cannabis I can safely operate a vehicle. I even pay more attention to traffic laws when I'm high than I do when I'm sober; I drive the speed limit, always double check my surroundings before making a turn or other maneuver and I'm constantly keeping track of other vehicles around me. I drive perfectly safe when high and might go as far to say that my use is somewhat medicinal for my mild ADHD and helps me focus on the task at hand.

I agree there needs to be regulation on this if and when it is legalized, but the fact stands that there is no currently accepted roadside test that can actually determine current level of intoxication from cannabis. With current tests and laws, if the test picks up even trace amounts of cannabis metabolites (could be from several weeks before), you are slapped with a DUI and lose your license... however, someone can get a prescription for Xanex or Valume or some other medication and even after being tested, would be free to go on their way.

My proposal... set age limits to 21, rookie drivers shouldn't be driving high. Ease punishments for people over 21 until a better testing method can be established.

I can currently take a shot of whiskey and drive legally, why not a small toke from a pipe?

OH, BTW... @occams_razor - FACT is that sober drivers make mistakes and die every day!! In fact, driving while tired has been shown to be almost if not more dangerous than driving while drunk.

Having been driving for nearly six years...and smoking for that long, has put me in many situations where I was driving stoned. Obviously the impairment is there...but I have driven both stoned and drunk, and to tell you the truth, I'd rather drive stoned. A lot less things to worry about.

I would like to see a study that proves that driving while completely sober is safe .
thousands of sober people get themselves into accidents everyday without the help of alchohol or drugs.
habitual pot smokers would probably do better than sober drivers .

I also agree that the diving simulator skewed the results

How about none of them? In my opinion they both put our life in danger. But what can we do if people get on their wheals exactly after they exit the Beer of the Month Contest or something like this?

This study is complete BS. It's a simulator, not an actual car. Even the author notes that it was difficult. Then the author states that the testers were not "model drivers" under the influence. How was their driving when sober on the simulator? You need to compare "apples to apples".

The other issue I have is the difference between alcohol and smoking. With alcohol, you can drink until you pass out, and some drivers have been caught with blood alcohol content's in the .03 and .04 ranges, which is VERY DEADLY. When you smoke, your body can only take ona certain % of the THC and you are "maxed out", and won't get any higher. I'd rather someone drive have 5 "cigs" rather than 5 vodka's.

http://profiles.friendster.com/johnnymorgan

Drive high all the time. I'm wayyy more focused & alert on whats around me. Everythings just SOOO still. It's so easy to concentrate...
Only thing is that everytime i look through my rearview... i think the car behind me has red & blue lights on top.. i have to blink a few times lmfao

I would like to suggest that neither is a good option, however I do know that alcohol increases your recklessness and your vision is impaired, whereas cannabis increases all of your senses, unreasonably so.

Lucille
http://www.meritcarhire.co.uk/



June 2013: American Energy Independence

Five amazing, clean technologies that will set us free, in this month's energy-focused issue. Also: how to build a better bomb detector, the robotic toys that are raising your children, a human catapult, the world's smallest arcade, and much more.


Online Content Director: Suzanne LaBarre | Email
Senior Editor: Paul Adams | Email
Associate Editor: Dan Nosowitz | Email
Assistant Editor: Colin Lecher | Email
Assistant Editor: Rose Pastore | Email

Contributing Writers:
Rebecca Boyle | Email
Kelsey D. Atherton | Email
Francie Diep | Email
Shaunacy Ferro | Email

circ-top-header.gif
circ-cover.gif
bmxmag-ps