Pubdate: Wed, 11 May 2016
Source: Atlanta Journal-Constitution (GA)
Copyright: 2016 Associated Press
Author: Joan Lowy, Associated Press


WASHINGTON (AP) - Motorists are being convicted of driving under the 
influence of marijuana based on arbitrary state standards that have 
no connection to whether the driver was actually impaired, says a 
study by the nation's largest auto club.

The problem is only growing as more states contemplate legalizing the 
drug. At least three, and possibly as many as 11 states, will vote 
this fall on ballot measures to legalize marijuana for medicinal or 
recreational use, or both. Legislation to legalize the drug has also 
been introduced in a half dozen states.

Currently, six states - Colorado, Montana, Nevada, Ohio, Pennsylvania 
and Washington - have set specific limits for THC, the chemical in 
marijuana that makes people high, in drivers' blood. Marijuana use is 
legal in those states for either recreational or medicinal purposes, 
with the exception of Ohio.

The laws presume a driver whose THC level exceeds the threshold is impaired.

But the study by AAA's safety foundation says the limits have no 
scientific basis and can result in innocent drivers being convicted 
and guilty drivers being released.

"There is understandably a strong desire by both lawmakers and the 
public to create legal limits for marijuana impairment in the same 
manner we do alcohol," said Marshall Doney, AAA's president and CEO. 
"In the case of marijuana, this approach is flawed and not supported 
by scientific research."

Another nine states, A study by the AAA Foundation for Safety says 
that it is not possible to judge a driver's impairment by the level 
of THC, marijuana's high-inducing ingredient, in the driver's blood. 
including some that have legalized marijuana for medical use, have 
zero-tolerance laws for driving and marijuana that make not only any 
presence of THC in a driver's blood illegal, but also the presence of 
its metabolites, which can linger in a driver's bloodstream for weeks 
after any impairment has dissipated.

That makes no sense, said Mark A. R. Kleiman, a New York University 
professor specializing in issues involving drugs and criminal policy. 
"A law against driving with THC in your bloodstream is not a law you 
can know you are obeying except by never smoking marijuana or never 
driving," he said.

The problem is that determining whether someone is impaired by 
marijuana, as opposed to having merely used the drug, is far more 
complex than the simple and reliable tests that have been developed 
for alcohol impairment.

The degree to which a driver is impaired by marijuana use depends a 
lot on the individual, the foundation said. Drivers with relatively 
high levels of THC in their systems might not be impaired, especially 
if they are regular users, while others with relatively low levels 
may be unsafe behind the wheel.

Some drivers may be impaired when they are stopped by police, but by 
the time their blood is tested they have fallen below the legal 
threshold because active THC dissipates rapidly. The average time to 
collect blood from a suspected driver is often more than two hours 
because taking a blood sample typically requires a warrant and 
transport to a police station or hospital, the foundation said.

In addition, frequent marijuana users can exhibit persistent levels 
of the drug long after use, while THC levels can decline more rapidly 
among occasional users.

Colorado's 5-nanogram limit for THC in blood "was picked out of thin 
air by politicians," said Robert Corry, a Denver criminal defense 
attorney. "Innocent people are convicted of DUI because of this."

Melanie Brinegar, who uses marijuana every day to control back pain, 
was stopped by police two years ago for having an expired license 
plate. The officer smelled marijuana and Brinegar acknowledged she 
had used the drug earlier in the day. Her blood test showed a level 
of 19 nanograms, well over the state limit. She was arrested and 
charged with driving while impaired.

Brinegar, 30, who lives in Denver, said she spent the next 13 months 
working 80 to 90 hours a week to pay for a lawyer to help her fight 
the charge and eventually was acquitted. People like herself will 
always test positive for THC whether they are high or not because of 
their frequent use, she said.

"It took a good amount of my time and my life," she said. "There is 
still that worry if I get pulled over (again)."

Studies show that using marijuana and driving roughly doubles the 
risk of a crash, Kleiman said. By comparison, talking on a handsfree 
cellphone while driving - legal in all states - quadruples crash 
risk, he said. A blood alcohol content of .12, which is about the 
median amount in drunken driving cases, increases crash risk by about 
15 times, he said.

When a driver has both been using marijuana and drinking alcoho, the 
two substances together greatly heighten impairment, he said.
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MAP posted-by: Jay Bergstrom