Drugged driving laws show little impact: All 50 states urged to adopt such laws

A new study by economists at the University of Colorado Denver and Montana State University reveals that so-called "per se" drugged driving laws have no discernible impact on traffic fatalities.

Per se laws set thresholds for controlled substances above which drivers are considered impaired.

Since 1990, 11 states have passed zero-tolerance drugged making it illegal to drive with detectable levels of a controlled substance in the system.  Five other states have passed similar laws specifying nonzero limits for controlled substances or their metabolites.
"These laws are intended to make the job of prosecuting drugged drivers easier," said Daniel Rees, professor of economics at the University of Colorado Denver who co-authored the study with D. Mark Anderson, assistant professor of economics at Montana State University. "In states without these laws, prosecutors must rely on field sobriety tests or evidence that a motorist was driving erratically in order to prove impairment."
The Office of National Drug Control Policy (ONDCP) recently announced a goal of reducing drugged driving by 10 percent within three years. In an effort to achieve this goal, the ONDCP is encouraging all 50 states to prohibit driving with detectable levels of a controlled substance in the system.

Although there is anecdotal evidence that the new drugged driving laws make prosecution easier, this is the first study to examine their effectiveness.
Using state-level data from the (FARS) for the period 1990-2010, Anderson and Rees examined the relationship between adopting controlled substance thresholds for drivers and .  They found that the relationship is statistically indistinguishable from zero and concluded that there is no evidence that these limits reduced traffic deaths. 
"Our study is particularly timely given that Washington voters recently passed Initiative 502, which legalized the recreational use of marijuana but prohibited driving with THC levels equal to, or greater than, five nanograms per milliliter of blood."  Anderson said. "Setting a THC standard for drivers may, in the future, be viewed by voters as a necessary complement to legalizing marijuana for recreational or medicinal use." 
The FARS data represent a census of all fatal injuries resulting from motor vehicle accidents in the United States and include information on when the accident took place.  Using this data, Anderson and Rees distinguished between nighttime and daytime traffic fatalities. They also distinguished between weekend and weekday .

Although the percentage of drivers testing positive for marijuana and other controlled substances is highest during the night and on weekends, they found no evidence that these laws, which have been adopted by 16 states, led to a reduction in traffic fatalities at either time. 

"There is strong evidence that drivers under the influence of marijuana have slower reaction times than who are not under the influence of marijuana," Rees said. "As currently implemented, these laws have no discernible impact on traffic fatalities."

The study, which is under review, is available as an IZA working paper at: www.iza.org/en/webcontent/pers … /index_html?key=4915

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Study shows medical marijuana laws reduce traffic deaths

Citation: Drugged driving laws show little impact: All 50 states urged to adopt such laws (2013, January 15) retrieved 17 June 2019 from https://phys.org/news/2013-01-drugged-laws-impact-states-urged.html
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Jan 15, 2013
ONDCP -- The very organization who has been given permission to LIE to the general public? That ONDCP?

commondreams . org/news2004/0312-06 . htm

"the GAO declared, in essence, that the truth or falsity of ONDCP's statements is irrelevant. "ONDCP is specifically charged with the responsibility for `taking such actions as necessary to oppose any attempt to legalize the use' of certain controlled substances such as marijuana,"

Are you really going to quote those who have permission to lie as if their statements are in any way credible?

Jan 15, 2013
re: slower reaction times- I seem to recall reading that drivers affected by marijuana also drive a lot slower- a consequence labelled as over compensation. It might also help with other things like road rage.

Jan 15, 2013
Ron Paulfan: Get over it! . . . Our Government lies so much and so often, only a Fool would believe anything or any 'Claim' made by them and their minions! One thought: They 'Think' they are so Superior, that they assume We Citizens 'Cannot Possibly' Be Bright enough to see through, and even 'Think' about their 'Proclamations' and Edicts! What a Sad and Sick state of affairs,and we continue to Fund these Deceitful bureaucrats 'ever-expansive Budgets' and wondering why We And our Country are in such deep Economic 'Mud'!

Roy J stewart,
Phoenix AZ
P.S. I advocate 'Legalizing All Natural/Organic 'Mind Altering Substances, as long as Nothing is made in or Requires a Laboratory!
Driving when Under the Influence of anything/and substance, must be 'strictly Verboten!

Jan 16, 2013
"There's no way to rule innocent men. The only power any government has is the power to crack down on criminals. Well, when there aren't enough criminals, one makes them. One declares so many things to be a crime that it becomes impossible for men to live without breaking laws." Ayn Rand - 1957

Jan 16, 2013
THC, it seems, can remain in the body for days and in the hair until it falls out. So, while the high is well over, a zero tolerance law might still get you arrested. I see the potential for a lot of abuse by those who do the enforcing.

Jan 17, 2013
Cannabis use is associated with only marginal increases in traffic accident risk, comparable to anti-histamines and penicillin.

An investigator from Aalborg University and the Institute of Transport Economics in Oslo assessed the risk of road accident associated with drivers' use of licit and illicit drugs, including amphetamines, analgesics, anti-asthmatics, anti-depressives, anti-histamines, benzodiazepines, cannabis, cocaine, opiates, penicillin and zopiclone (a sleeping pill). His study reviewed data from 66 separate studies evaluating the use of illicit or prescribed drugs on accident risk; the study found that cannabis was associated with minor, but not significantly increased odds of traffic injury (1.06) or fatal accident (1.25). By comparison, opiates (1.44), benzodiazepine tranquillizers (2.30), anti-depressants (1.32), cocaine (2.96), amphetamines (4.46), and the sleeping aid zopiclone (2.60) were all associated with a greater risk of fatal accident than cannabis. Anti-hi

Jan 17, 2013
Unlike with alcohol, the accident risk caused by cannabis, particularly among those who are not acutely intoxicated, appears limited because subjects under its influence are generally aware of their impairment and compensate to some extent, such as by slowing down and by focusing their attention when they know a response will be required. [Allison Smiley. Marijuana: On-Road and Driving Simulator Studies]

This response is the opposite of that exhibited by drivers under the influence of alcohol, who tend to drive in a more risky manner proportional to their intoxication.[United Kingdom's Advisory Council on the Misuse of Drugs. The Classification of Cannabis Under the Misuse of Drugs Act of 1971. 2002: See specifically: Chapter 4, Section 4.3.5: "Cannabis differs from alcohol; ... it seems not to increase risk-taking behavior. This may explain why it appears to play a smaller role than alcohol in road traffic accidents."]

Jan 17, 2013
Is Driving High on Marijuana Safer Than Driving Drunk? [ or driving sober?!! ]
For decades, marijuana advocates have argued that pot has a significantly different effect on driving ability than alcohol. But if you take the word of one auto insurance company, stoned is actually the safest way to drive. 4AutoinsuranceQuote.org is making that case based on years' worth of scientific studies, including some from the US National Highway Transportation Safety Administration that found motorists under the influence of marijuana tended to drive slower and have accident responsibility rates lower than those of drug-free drivers.

Jan 17, 2013
One study, entitled "Medical Marijuana Laws, Traffic Fatalities, and Alcohol Consumption" conducted in November 2011 provides evidence that marijuana is a safer substitute for alcohol when it comes to health and also makes for safer drivers. Drivers who had been using marijuana were found to drive slower, according to a 1983 study done by U.S. National Highway Transportation Safety Administration (NHTSA). This was seen as a factor in their favor, since drivers who drank alcohol usually drove faster and that is part of the reason they had accidents. Marijuana users were able to drive straight and not have any trouble staying in their own lanes when driving on the highway, according to a NHTSA done in 1993 in the Netherlands. The study determined also that the use of marijuana had very little effect on the person's overall driving ability.

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