A controversial measure which sets a THC-blood limit for Colorado motorists -- a concept which has failed six times in the last three years in the state legislature -- passed in the state Senate, Tuesday.
The Senate passed House Bill 1325 on a 24-11 vote and it now heads to Gov. John Hickenlooper who has said he supports a marijuana DUI framework for the state.
Under HB 1325, drivers caught with 5 nanograms of THC, the psychoactive ingredient in marijuana which produces the "high" sensation, in their blood would be considered too stoned to drive and could be ticketed similarly to a person who was considered too drunk to drive.
The bill, which was just introduced last week, is an exact copy of another bill which was killed by the Senate earlier this year. Also last week, an identical measure which had been amended to House Bill 1317, the recreational marijuana regulatory framework proposal, was stripped from the bill in Senate committee. But this newly introduced stand-alone version appears poised to now become law.
As in previous years when marijuana DUI bills have come up for debate, opponents say that the 5 nanogram standard is too low for frequent pot smokers, especially medical marijuana patients, who regularly have this level of THC in the bloodstream and therefore, if passed, these people would lose their driving privileges, The Denver Post reports.
But HB-1325 allows for a person who has been charged with having 5 nanograms of THC in their blood to rebut the charge that they are too impaired to drive.
"For example, if you did not exhibit poor driving, you can put that on as evidence to say, 'Look my driving was not poor, I'm not unsafe to operate a motor vehicle,'" Rep. Mark Waller (R-Colorado Springs) said during earlier hearings of an identical bill which was killed.
All of the previous failed marijuana DUI bills were "per se" bills -- meaning if a driver tested above the legal 5 nanogram limit, the result would be an automatic conviction nearly every time.
But are drivers measurably impaired while under the influence of marijuana like they clearly are when under the influence of alcohol? That has been one of the core questions opponents of the bill have been asking about bills like these each year they are introduced. Westword spoke to Attorney Leonard Frieling in 2012 over last year's marijuana DUI bill who described the clear correlation between blood alcohol level and driving impairment -- the higher the blood alcohol level, the more impaired drivers are. But he questions the correlation between marijuana blood levels and driving impairment saying to Westword, "that appears not to hold true as cleanly with cannabis. So talking about impaired driving is one thing, but trying to give a number a meaning it doesn't have is something else entirely."
Last year Sen. Pat Steadman (D-Denver) spoke out about the issues that make marijuana blood limits problematic like the fact that THC is fat-soluable, so blood limits could remain above the 5 nanogram limit for days after the user last legally smoked pot, CBS4 reported. The user would not appear stoned, but legally they could still be considered impaired.
With this thinking in mind, Steadman tried to exempt medical marijuana patients in the bill -- as he'd done in years past -- but ultimately failed, according to Fox31.
This fact of THC's different effect on the body than alcohol's was stunningly shown in 2011 by Westword pot reporter William Breathes. After a night of sleep and not smoking pot for 15 hours, a sober Breathes still tested nearly three times higher than the proposed legal limit.
To add confusion to the matter, Washington state television station KIRO recently assembled a group of volunteers, had them smoke pot and set them loose on a driving test course to try and answer the question: How high is too high to drive?
The less-than-scientific results, while entertaining, unfortunately don't add much clarity to the question at hand. A regular smoker of marijuana tested above the legal limit to begin with, yet drove without much of a problem. Two casual smokers also navigated the course without incident. However, after smoking more marijuana, driving ability began to devolve quickly.
Washington state voters, along with voters in Colorado, passed recreational marijuana amendments last November, but Washington, unlike Colorado, already passed a marijuana DUI bill in 2012 setting the legal impairment standard at 5 nanograms in the state.
And in Washington, the enforcement of the law ultimately comes down to common sense. Explains Bob Calkins, a Washington State Patrol spokesman, to The Oregonian, "We don't just pull people over and draw blood... If you're driving OK, we're not going pull you over. But driving impaired is still driving impaired." Watch KIRO's full stoned driving segment here.