Pubdate: Sun, 10 Feb 2013
Source: Denver Post (CO)
Copyright: 2013 The Denver Post Corp
Contact:  http://www.denverpost.com/
Details: http://www.mapinc.org/media/122
Author: John Ingold

SOBER LOOK AT STONED DRIVING

When a long-running legislative serial opens its third season at the 
state Capitol on Tuesday, it will start with a twist.

Two relatively new studies promise to shed more light-though not 
necessarily more consensus - on the debate around driving while 
stoned. The first, published in BMJ, the journal of the British 
Medical Association, shows why marijuana-impaired driving is 
dangerous. The second, from a University of Colorado Denver 
professor, questions what laws intended to crack down on stoned 
driving accomplish.

They both will become part of the plot of one of the most extended 
legislative soap operas going under the dome: The battle to set a 
limit for how high is too high to drive.

This year's bill on the subject, House Bill 1114, gets its first 
committee hearing Tuesday afternoon.

"I am very hopeful that it is going to get through this year," said 
state Rep. Mark Waller, a Colorado Springs Republican taking his 
third turn as a sponsor of the marijuana-driving bill."With the 
passage of Amendment 64, we need a presumptive limit on the books."

The premise here is fairly simple: Supporters of the bill say that, 
to combat stoned driving, there should be a limit to how much 
marijuana people can have in their systems before they are presumed 
impaired. The idea is similar to the 0.08 percent blood-alcohol level 
for booze and would make it easier for prosecutors to win convictions 
in stoned-driving cases.

It's currently illegal to drive stoned, but prosecutors must prove 
impairment in each case.

Bill sponsors this year will try again to peg the marijuana limit at 
5 nanograms of THC- the psychoactive stuff in marijuana-per 
milliliter of blood.

But the simple premise belies the complicated debate beneath, as the 
two studies show.

Published last year by researchers from Canada, the report in BMJ 
analyzes the results of nine studies worldwide on the impacts of 
heavy marijuana use and driving. And out of the disparate studies, 
the analysis pulls a concise conclusion.

"Acute cannabis consumption nearly doubles the risk of a collision 
resulting in serious injury or death," the study states.

But a new study by CU Denver professor Daniel Rees and Montana State 
University professor D. Mark Anderson suggests stoned-driving limits 
don't impact traffic fatalities. Rees said he and Anderson looked at 
fatality data from 16 states that adopted marijuana-limit laws 
between 1990 and 2010 and found no statistically significant 
difference between states that did and didn't have such laws.

"We cut the data a bunch of different ways, and the estimate just 
came back zero, zero, zero, zero, zero," Rees said. "... All we can 
conclude is that, as currently implemented, they are not effective."

The new studies add to the ongoing debate about marijuana, impairment 
and whether the 5-nanogram limit will allow stoned drivers to slip 
free or cause sober drivers to be convicted. That debate alone 
tripped up three previous versions of the bill during the past two years.

One tweak to the bill this year, though, could smooth its path. 
Instead of making the 5-nanogram measure a "per se" limit-which would 
lead to virtually automatic convictions for those who test above it - 
this year's bill would allow defendants greater leeway to argue that 
they weren't impaired, even if they hit the 5-nanogram limit.

"We would like per se," said Thomas Raynes, the executive director of 
the Colorado District Attorneys' Council. "But it's a step in the 
right direction. At this point in time, we'll take a step inthe right 
direction."
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MAP posted-by: Jay Bergstrom