Category Archives: Drugged Driving
I've discussed in the past how difficult it is (1) to recognize and identify whether a person's driving ability is impaired by marijuana, and (2) to prove with observable and chemical evidence the existence of that impairment. See, for example, DUI Marijuana: Does Marijuana Impair Driving? and Driving + Trace of Marijuana = DUI.
The following news story does an excellent job of highlighting some of the issues of a growing problem:
New Wrinkle in Pot Debate: Stoned Driving
Denver, CO. March 18 – Angeline Chilton says she can't drive unless she smokes pot. The suburban Denver woman says she'd never get behind the wheel right after smoking, but she does use medical marijuana twice a day to ease tremors caused by multiple sclerosis that previously left her homebound.
"I don't drink and drive, and I don't smoke and drive," she said. "But my body is completely saturated with THC."
Her case underscores a problem that no one's sure how to solve: How do you tell if someone is too stoned to drive?
States that allow medical marijuana have grappled with determining impairment levels for years. And voters in Colorado and Washington state will decide this fall whether to legalize the drug for recreational use, bringing a new urgency to the issue.
A Denver marijuana advocate says officials are scrambling for limits in part because more drivers acknowledge using the drug.
"The explosion of medical marijuana patients has led to a lot of drivers sticking the (marijuana) card in law enforcement's face, saying, `You can't do anything to me, I'm legal,'" said Sean McAllister, a lawyer who defends people charged with driving under the influence of marijuana.
It's not that simple. Driving while impaired by any drug is illegal in all states.
But it highlights the challenges law enforcement officers face using old tools to try to fix a new problem. Most convictions for drugged driving now are based on police observations, followed later by a blood test.
Authorities envision a legal threshold for pot that would be comparable to the blood-alcohol standard used to determine drunken driving.
But unlike alcohol, marijuana stays in the blood long after the high wears off a few hours after use, and there is no quick test to determine someone's level of impairment — not that scientists haven't been working on it.
Dr. Marilyn Huestis of the National Institute on Drug Abuse, a government research lab, says that soon there will be a saliva test to detect recent marijuana use.
But government officials say that doesn't address the question of impairment.
"I'll be dead — and so will lots of other people — from old age, before we know the impairment levels" for marijuana and other drugs, said White House drug czar Gil Kerlikowske.
Authorities recognize the need for a solution. Marijuana causes dizziness, slowed reaction time and drivers are more likely to drift and swerve while they're high…
Physicians say that while many tests can show whether someone has recently used pot, it's more difficult to pinpoint impairment at any certain time.
Urine and blood tests are better at showing whether someone used the drug in the past — which is why employers and probation officers use them. But determining current impairment is far trickier.
"There's no sure answer to that question," said Dr. Guohua Li, a Columbia University researcher who reviewed marijuana use and motor vehicle crashes last year.
His survey linked pot use to crash risk, but pointed out wide research gaps. Scientists do not have conclusive data to link marijuana dosing to accident likelihood; whether it matters if the drug is smoked or eaten; or how pot interacts with other drugs.
The limited data has prompted a furious debate.
Proposed solutions include setting limits on the amount of the main psychoactive chemical in marijuana, THC, that drivers can have in their blood. But THC limits to determine impairment are not widely agreed upon.
Two states place the standard at 2 nanograms per milliliter of blood. Others have zero tolerance policies. And Colorado and Washington state are debating a threshold of 5 nanograms.
Such an attempt failed the Colorado Legislature last year, amid opposition from Republicans and Democrats. State officials then set up a task force to settle the question — and the panel couldn't agree.
This year, Colorado lawmakers are debating a similar measure, but its sponsors concede they don't know whether the "driving while high" bill will pass.
In Washington state, the ballot measure on marijuana legalization includes a 5 nanogram THC limit.
The measure's backers say polling indicates such a driving limit could be crucial to winning public support for legalization…
The White House, which has a goal of reducing drugged driving by 10 percent in the next three years, wants states to set a blood-level standard upon which to base convictions, but has not said what that limit should be.
Administration officials insist marijuana should remain illegal, and Kerlikowske called it a "bogus argument" to say any legal level of THC in a driver is safe.
But several factors can skew THC blood tests, including age, gender, weight and frequency of marijuana use. Also, THC can remain in the system weeks after a user sobers up, leading to the anxiety shared by many in the 16 medical marijuana states: They could be at risk for a positive test at any time, whether they had recently used the drug or not.
(Thanks to Andre Campos.)
I've received feedback concerning my post five days ago (Let's Define the Objective: Preventing Drinking — or Traffic Fatalities?), and there seems to be some skepticism concerning the relative dangers of drunk driving versus driving while either distracted, drowsy or drugged. As I said in my post, the focus should be on the relative dangers to human life – not on whether alcohol is involved. So let's take a look at that…
The President of MADD has been quoted in the Los Angeles Times as saying: "We don’t want cell phones and drowsy driving to become the next hot-button issue for the country, because they don’t even compare with the problem of drunk driving." The Partnership for Safe Driving, a non-profit organization in Washington, D.C., responded:
Let’s examine the claim. During the year 2001, the government estimates that 17,448 – or 41 percent – of the deaths on our nation’s highways were "alcohol-related." In addition, approximately 275,000 – or 16 percent – of the injuries were attributed to alcohol. Since the rate of fatalities is so high, and so much higher than the rate of injuries, let’s take a closer look at that statistic.
Of the 17,448 fatalities, 2,555 occurred in crashes where alcohol was detected but no one was over the legal limit. In these crashes, alcohol may not have been the primary factor in the crash; speed, distraction or fatigue could have been. That leaves 14,893 deaths that can actually be attributed to alcohol. However, of these, 1,770 were intoxicated pedestrians and cyclists who walked out in front of the vehicles of sober drivers. They had nothing to do with drunk driving.
The Partnership questions why these deaths were thrown in with what is normally presented as a drunk driving statistic. That leaves 13,123 deaths that can be attributed to intoxicated drivers. Of these, a staggering 8,308 were intoxicated drivers who killed themselves in crashes. That leaves 4,815 deaths in which intoxicated drivers killed someone other than themselves….
How do these figures compare with cell phone use?
To date, the Harvard Center for Risk Analysis has provided the only nationwide estimates of cell phone involvement in fatal and injury-producing crashes. Researchers there report that cell phones are now a factor in approximately 2,600 fatalities annually and 330,000 moderate to critical injuries. But because the data on cell phone use by motorists are still limited, the range of uncertainty is wide. Researchers say that the range for fatalities is 800 to 8,000 annually, and the range for injuries is 100,000 to one million annually….
And fatalities caused by tired and sleepy drivers?
As with cell phone use, the influence of drowsy driving and fatigue on crashes often is not known unless the driver survives the crash and admits to having nodded off. Unlike both alcohol involvement and cell phone use, there is no scientific method even available for determining its presence. That said, the government estimates conservatively that 1,500 people are killed annually as a result of motorists who fall asleep at the wheel, and another 71,000 are injured annually in such crashes. However, the National Sleep Foundation believes that drowsy driving and fatigue often play a role in crashes that are attributed to other causes. For example, the government lists driver inattention as the primary cause of approximately one million police-reported crashes each year. The sleep foundation points out that drowsy driving and fatigue make such lapses of attention more likely….
Confirmation of this data has come from a study ("Drunk or Drowsy?") jointly undertaken by the AAA Foundation for Traffic Safety and the National Highway Traffic Safety Administration (NHTSA), which found that “Nearly nine out of every ten police officers…reported they had stopped a driver who they believed was drunk, but turned out to be drowsy…. According to NHTSA data, up to 100,000 police-reported crashes annually involve drowsiness or fatigue as a principal causal factor.”
Interestingly, “89 percent of police officers agreed that drowsy driving is as dangerous as drunk driving”.
MADD’s passionate fixation on drunk driving appears to be blinding it to the importance of other, possibly more significant, causes of traffic fatalities.
It is against the law to drive while under the influence of marijuana. It has always been assumed that cannabis, like alcohol, impairs the perception, coordination, reflexes and judgment necessary for the safe operation of a motor vehicle. And, of course, there have been governmental studies addressing the question: Does marijuana impair driving?
Interestingly, however, the findings do not necessarily support popular opinion….
On the one hand, the California Department of Justice has found that marijuana undoubtedly impairs psychomotor abilities that are functionally related to driving and that driving skills may be impaired, particularly at high-dose levels or among inexperienced users. "Marijuana and Alcohol: A Driver Performance Study", California Office of Traffic Safety Project No. 087902 (Sept. 1986).
Contradicting these conclusions, however, are two federal studies. The U.S. Department of Transportation conducted research with a fully interactive simulator on the effects of alcohol and marijuana, alone and in combination, on driver-controlled behavior and performance. Although alcohol was found consistently and significantly to cause impairment, marijuana had only an occasional effect. Also, there was little evidence of interaction between alcohol and marijuana. Accidents and speeding tickets reliably increased with alcohol, but no marijuana or combined alcohol-marijuana effects were noted. "The Effects of Alcohol on Driver-Controlled Behavior in a Driving Simulator, Phase I", DOT-HS-806-414.
A more recent report entitled "Marijuana and Actual Performance", DOT-HS-808-078, noted that "THC is not a profoundly impairing drug….It apparently affects controlled information processing in a variety of laboratory tests, but not to the extent which is beyond the individual’s ability to control when he is motivated and permitted to do so in driving". The study concluded that:
An important practical objective of this study was to determine whether degrees of driving impairment can be actually predicted from either measured concentration of THC in plasma or performance measured in potential roadside "sobriety" tests of tracking ability or hand and posture stability. The results, like many reported before, indicated that none of these measures accurately predicts changes in actual performance under the influence of THC…
The researchers found that it "appears not possible to conclude anything about a driver’s impairment on the basis of his/her plasma concentrations of THC and THC-COOH determined in a single sample".
Note: "THC" stands for Delta-9-tetrahydrocannabinol, which is the intoxicating ingredient in marijuana. THC is fairly quickly converted by the body into inert metabolites, which can stay in the body for hours or even days. It is these metabolites that police blood tests in DUI arrests detect and measure. In other words, (1) marijuana may not impair driving ability at all, and (2) the blood "evidence" only measures an inactive substance which may have been there for days. thc & marijuana detox
In the This-Is-Getting-Ridiculous department:
Blood Test for Marijuana Unreliable for DUI Penalty
Lexington, KY. Jan. 17 - Once again, a bill that seeks to punish prior use of a controlled substance with an automatic DUI conviction is before the Kentucky legislature.
Like its predecessors, Senate Bill5 cleverly attempts to bootstrap an ill-advised rule regarding all drugs onto a rule created for the purpose of measuring alcohol impairment. Under SB5, a driver who tests positive for traces of marijuana can be convicted of "driving under the influence" even if that driver is unimpaired at the time of arrest.
While such laws do little to actually make roadways safer, they do send many innocent people to jail and saddle them with criminal records for the rest of their lives. Current Kentucky DUI law requires prosecutors to prove that a suspect was impaired while driving. SB5 seeks to circumvent current evidentiary standards by removing this requirement. If lawmakers want to clog court dockets, cost taxpayers more money and make it tougher for Kentuckians to find and retain employment, then this is the bill to support…
Moreover, the test referred to in SB5 is not a test for marijuana impairment, but merely a test for marijuana’s presence, which is not what DUI laws are supposed to punish.
The effect and perhaps even the aim of legislation like SB5 is to punish prior drug use — predominantly marijuana use — by convicting drivers of DUI without scientifically reliable evidence that they were operating a vehicle while under the influence of anything.
"Zero-tolerance" laws are more than unjust; they are scientifically unsound, which is exactly why not one single state applies such a rule to alcohol. Furthermore, these laws are even less suited for marijuana, the traces of which are detectable by drug tests long after its intoxicating effects have worn off…
A driver with high levels of THC (the active psychotropic ingredient in marijuana) in the blood may not be impaired in any manner if time has passed since the substance was last used. The inability to accurately measure marijuana impairment is why both the National Highway Traffic Safety Administration and the National Institute on Drug Abuse have stated that marijuana impairment testing via blood sampling is unreliable.
Driving under the influence of any substance is dangerous and should not be tolerated, but sending innocent people to jail for DUI using methods incapable of accurately measuring impairment is not the answer.
(Thanks to Nathan Miller)
Interesting review concluding that certain common prescription drugs are causing a craving for alcohol and, possibly, alcoholism:
Alcohol Cravings Induced via Increased Serotonin
There is an alarming connection between alcoholism and the various prescription drugs that increase serotonin. The most popular of those drugs are: PROZAC, ZOLOFT, PAXIL, LUVOX, SERZONE, EFFEXOR, ANAFRANIL, and the new diet pills, FEN-PHEN and REDUX. For seven years numerous reports have been made by reformed alcoholics (some for 15 years and longer) who are being "driven" to alcohol again after being prescribed one of these drugs. And many other patients who had no previous history of alcoholism have continued to report an "overwhelming compulsion" to drink while using these drugs…
For some time we did not have specific medical documentation to help us understand why this was happening. Could it be that Prozac, Zoloft, Paxil, etc., being mood altering substances, were removing the inhibitions that individuals had placed upon themselves to stop their additions? But beyond this mood altering effect of Prozac, etc., there seemed to be a physiological cause for this alcoholic obsession as well. There were reports of people who rarely drank before Prozac, etc., consuming excessive amounts of alcohol after starting usage of these various drugs.
In November of 1994 Yale published a study that gave us one answer to the alcohol cravings associated with these drugs. The study demonstrated that an increase in brain levels of either of two neurotransmitters (brain hormones), serotonin or noradrenalin, produces: #1 a craving for alcohol, #2 anger, #3 anxiety. They found this to be especially true for those who have a history of alcoholism…
The Yale study mentioned is Specificity of Ethanol-like Effects Elicited in Serotonergic and Noradrenergic Mechanisms," ARCHIVES OF GENERAL PSYCHIATRY, Vol. 51, Issue 11, pgs 898-911.
(Thanks to William C. Head.)