DENVER -- It's settled. Pot, at least certain amounts of it, will
soon be legal under state laws in Washington and Colorado. Now,
officials in both states are trying to figure out how to keep stoned
drivers off the road.
Colorado's measure doesn't make any changes
to the state's driving-under-the-influence laws, leaving lawmakers and
police to worry about its effect on road safety.
"We're going to have more impaired drivers," warned John Jackson, police chief in the Denver suburb of Greenwood Village.
Washington's
law does change DUI provisions by setting a new blood-test limit for
marijuana - a limit police are training to enforce, and which some
lawyers are already gearing up to challenge.
"We've had decades of
studies and experience with alcohol," said Washington State Patrol
spokesman Dan Coon. "Marijuana is new, so it's going to take some time
to figure out how the courts and prosecutors are going to handle it. But
the key is impairment: We will arrest drivers who drive impaired,
whether it be drugs or alcohol."
Drugged driving is illegal, and
nothing in the measures that Washington and Colorado voters passed this
month to tax and regulate the sale of pot for recreational use by adults
over 21 changes that. But law enforcement officials wonder about
whether the ability to buy or possess marijuana legally will bring about
an increase of marijuana users on the roads.
Statistics gathered
for the National Highway Traffic Safety Administration showed that in
2009, a third of fatally injured drivers with known drug test results
were positive for drugs other than alcohol. Among randomly stopped
weekend nighttime drivers in 2007, more than 16 percent were positive
for drugs.
Marijuana can cause dizziness and slowed reaction time, and drivers are more likely to drift and swerve while they're high.
Marijuana
legalization activists agree people shouldn't smoke and drive. But
setting a standard comparable to blood-alcohol limits has sparked
intense disagreement, said Betty Aldworth, outreach director for
Colorado's Campaign to Regulate Marijuana Like Alcohol.
Most convictions for drugged driving currently are based on police observations, followed later by a blood test.
"There
is not yet a consensus about the standard rate for THC impairment,"
Aldworth said, referring to the psychoactive chemical in marijuana.
Unlike
portable breath tests for alcohol, there's no easily available way to
determine whether someone is impaired from recent pot use.
There
are different types of tests for marijuana. Many workplaces test for an
inactive THC metabolite that can be stored in body fat and remain
detectable weeks after use. But tests for current impairment measure for
active THC in the blood, and those levels typically drop within hours.
According
to the National Highway Traffic Safety Administration, peak THC
concentrations are reached during the act of smoking, and within three
hours, they generally fall to less than 5 nanograms per milliliter of
blood - the same standard in Washington's law, one supporters describe
as roughly equivalent to the .08 limit for alcohol.
Two other
states - Ohio and the medical marijuana state of Nevada - have a limit
of 2 nanograms of THC per milliliter. Pennsylvania's health department
has a 5-nanogram guideline that can be introduced in driving violation
cases, and a dozen states, including Illinois, Arizona, and Rhode
Island, have zero-tolerance policies.
In Washington, police still
have to observe signs of impaired driving before pulling someone over,
Coon said. The blood would be drawn by a medical professional, and tests
above 5 nanograms would automatically subject the driver to a DUI
conviction.
Supporters of Washington's measure said they included
the standard to allay fears that legalization could prompt a
drugged-driving epidemic, but critics call it arbitrarily strict. They
insist that medical patients who regularly use cannabis would likely
fail even if they weren't impaired.
They also worry about the
law's zero-tolerance policy for those under 21. College students who
wind up convicted even if they weren't impaired could lose college
loans, they argue.
Jon Fox, a Seattle-area DUI attorney, said he's
interested in challenging Washington's new standard as
unconstitutional. Under due process principles, he said, people are
entitled to know what activity is prohibited. If scientists can't tell
someone how much marijuana it will take for him or her to test over the
threshold, how is the average pot user supposed to know?
By
contrast, he noted, the science on alcohol is well established. Some
states publish charts estimating how many drinks it will take a person
of a certain weight over a certain time to reach .08.
But such a
challenge to Nevada's marijuana DUI limit failed in 2002, when the state
Supreme Court ruled that the Legislature has broad authority to set
driving standards. The U.S. Supreme Court declined to review that case,
said Las Vegas DUI attorney Michael Becker.
"Marijuana affects
everyone differently," Becker said. "The prevailing opinion of forensic
toxicologists is that a 2-nanograms standard, such as exists in Nevada,
absolutely results in convictions where individuals are not actually
under the influence. But the 5-nanograms standard more closely
approaches the mean threshold of prevailing opinion."
Colorado's
legalization measure didn't set a driving standard - an intentional
omission by the activists who wrote it because the issue has proven
divisive. Lawmakers in Colorado, which has an established medical
marijuana industry, have tried but failed three times to set a THC
driving limit.
Drugged driving cases in Colorado were up even
before the legalization vote. In 2009, the state toxicology lab obtained
791 THC-positive samples from suspected impaired drivers. Last year, it
had 2,030 THC-positive samples.
Colorado lawmakers are preparing to take up driving standards yet again when they convene next year.
"I
believe a 5-nanogram limit will save lives," said Colorado Republican
state Sen. Steve King, sponsor of previous driving-high bills.
Associated Press