Pubdate: Sat, 07 Feb 2015
Source: Detroit News (MI)
Copyright: 2015 The Detroit News
Contact:  http://www.detroitnews.com/
Details: http://www.mapinc.org/media/126
Author: David Shepardson

POT USE DOESN'T INCREASE CRASH RISK

NHTSA Study Comes As States Legalize Marijuana

Washington - A government study released late Friday found no 
evidence that marijuana use leads to a higher risk of getting into a 
traffic crash.

But safety advocates believe it is still dangerous to drive after 
smoking significant amounts of marijuana, and the government plans 
more testing.

The National Highway Traffic Safety Administration said a 20-month 
survey of drivers in 2013 and 2014 found that while drinking 
dramatically raises the chance of a crash, there was no evidence that 
marijuana use is statistically significant in boosting wreck rates.

The agency said the issue is of growing importance in the wake of 
marijuana being legalized in Colorado, Oregon, Alaska and Washington 
state for recreational use.

In Michigan, eight cities approved decriminalization measures last 
year for marijuana: Berkley, Huntington Woods, Mount Pleasant, 
Pleasant Ridge, Port Huron, Saginaw, Oak Park and Hazel Park.

The report's findings were based on two surveys. The National 
Roadside Survey, which collected information from volunteer drivers 
at 300 research checkpoints across the U.S., and a second study - the 
largest of its kind ever conducted - that assessed whether marijuana 
use by drivers is associated with greater risk of crashes. That 
study, in Virginia, gathered data over 20 months from more than 3,000 
drivers who were in crashes, as well as a comparison group of 6,000 
drivers who did not crash.

The percentage of drivers with evidence of marijuana in their system 
increased from 8.6 percent in 2007 to 12.6 percent in the study, NHTSA said

Marijuana users were about 25 percent more likely to be involved in a 
crash than drivers with no evidence of marijuana use. But that's 
because other factors - especially that more younger men are involved 
in crashes, NHTSA said - rather than marijuana use itself.

By comparing marijuana use among those in crashes and those who 
weren't, the safety agency said "other factors, such as age and 
gender, appear to account for the increased crash risk among marijuana users."

Former Acting NHTSA Administrator David Kelly said the study results 
shouldn't be interpreted as a flat declaration that driving after 
smoking pot use is safe. Further research is needed, NHTSA said, 
"before more definitive conclusions about drug use and crash risk can 
be reached."

"You can't say that driving while stoned is not a risk. We know it 
debilitates the ability to drive safely," he said.

Mason Tvert, director of communications for the Marijuana Policy 
Project in Denver, added that the group doesn't want people driving 
after significant marijuana use.

The United States doesn't good a good job of testing for marijuana 
use among drivers, Kelley said. Police, he noted, often don't bother 
to test for marijuana if a driver already has tested positive for 
drunken driving.

It's difficult to determine at what level marijuana use may impair 
driving, the government said, because - unlike with alcohol testing - 
there aren't precise levels of chemicals from marijuana proven to 
correlate with impairment.

Drugged drivers

Michigan had the 12th highest rate of drugged drivers in the country 
from 2006-09, says the Substance Abuse and Mental Health Services 
Administration.

While all states prohibit driving under the influence of drugs, 
there's significant variation in the minimum acceptable levels of 
marijuana or its traces in a driver's system.

Sixteen states, including Michigan, forbid any presence of prohibited 
drugs, while five others have specific limits for marijuana. In 
October, Gov. Rick Snyder signed legislation allowing police to 
conduct a roadside analysis for drugs, in addition to alcohol.

Mothers Against Drunk Driving has made drug use behind the wheel a 
bigger focus. MADD this year changed its mission statement to include 
"help fight drugged driving."

"MADD hopes to bring awareness to the growing threat of drugged 
driving on our roadways, much in the same way we have with drunk 
driving since our founding in 1980," the group says on its website.

"While the substances are different, the results are the same - 
needless deaths and injuries."

NHTSA is conducting additional studies to further understand the risk 
of driving after drug use, including the Washington State Roadside 
Survey, "which will assess risk in a state where marijuana has 
recently been legalized."

It also is on board with the National Institute on Drug Abuse for a 
simulator study to assess how drivers under the influence of drugs 
behave behind the wheel, the agency said. Ongoing research, it said, 
"will refine our understanding of when marijuana use by drivers" 
increases the effect it has on driving.

"Researchers have developed a deep body of knowledge about the link 
between drinking, driving and risk. We know drunk driving kills," 
added NHTSA Administrator Mark Rosekind.

"The combined message of these two surveys is that our work to 
understand and combat drunk driving is paying off, but that we have 
much to learn about how illegal drugs and prescription medicines 
affect highway safety - and that developing that knowledge is urgent, 
because more and more drivers have these drugs in their systems."

Weekend numbers fall

As marijuana use behind the wheel is rising, the incidence of driving 
on weekends after drinking has fallen sharply.

The study said the proportion of drunken drivers on the roads has 
fallen by 80 percent since 1973. The study found about 1.5 percent of 
weekend drivers had blood-alcohol concentrations equal to being 
legally intoxicated, 0.08 percent or above.

The proportion of drivers with any alcohol in their system declined 
by about 30 percent from 2007 to 2014.

Drivers with a breath alcohol level of 0.08 percent were about four 
times more likely to crash than sober drivers, NHTSA said, while 
drivers with an alcohol level of 0.15 percent were 12 times more 
likely to crash than sober drivers.
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MAP posted-by: Jay Bergstrom