DENVER — A marijuana blood limit for drivers was rejected Tuesday for a third time in Colorado, as lawmakers from both parties argued about how to fairly gauge whether someone is too stoned to get behind the wheel.
The bill would have made Colorado the third state in the nation with a blood-level limit for marijuana, much as the nation has a blood-alcohol limit of .08.
Currently, drugged-driving convictions depend on officer observations.
The Colorado Senate fell a single vote short on the bill setting a drivers' blood standard for THC, the psychoactive ingredient in marijuana. The measure failed on a 17-17 tie, one vote short of the number needed to advance it.
Earlier Tuesday, the state House signed off again on the bill that would limit drivers to 5 nanograms of THC per milliliter of blood. Sponsors talked about Colorado's rising arrest rates for people driving under the influence of drugs, as well as data from the National Highway Traffic Safety Administration showing more drivers in fatal accidents test positive for marijuana.
"It is past time to get this done," said Republican Rep. Mark Waller, sponsor of the bill.
However, marijuana activists and some lawmakers from both parties argued that the blood standard is an unfair measure of driver impairment. They pointed out that more than 90 percent of Colorado's drugged-driving criminal cases already end in convictions, so they questioned whether the 5 nanogram limit would change behavior.
"I don't think it'll make our roads any safer," argued Democratic Sen. Pat Steadman of Denver.
Some Republicans opposed the bill, arguing that the measure considered Tuesday should have targeted more than just marijuana use.
Opponents tried to amend the bill to exempt state-certified medical marijuana patients from the limit. The amendment failed.
"Impaired is impaired, whether you have a (medical marijuana) card or don't have a card," argued Republican Sen. Steve King.
After the amendment failed, the entire bill collapsed. Its fate appeared to hinge on the absence Tuesday of a lone senator _ Republican Sen. Nancy Spence of the Denver suburb of Centennial.
Spence opposed the DUI measure last year, but changed course and gave the marijuana DUI a single-vote margin of victory in the Senate earlier this year. That bill didn't clear the House, though, as that chamber was embroiled in a last-minute standoff over civil unions for same-sex couples.
The pot bill came back to lawmakers in a special legislative session. However, Spence has been out of town all week and didn't make it to Denver for the vote. Her absence meant defeat for the bill.
While it's already illegal to drive while impaired by drugs, states have taken different approaches to the issue. More than a dozen states, including Arizona, Michigan, Illinois, Iowa, and Rhode Island, have a zero-tolerance policy for driving with any presence of an illegal substance, according to the National Conference of State Legislatures. Minnesota has the same policy but exempts marijuana.
Nevada, which is among the 16 states that allow medical marijuana, and Ohio have a 2 nanogram THC limit for driving. Pennsylvania has a 5 nanogram limit, but that's a state Health Department guideline, which can be introduced in driving violation cases.
Voters in Washington state will consider a 5 nanogram THC driving limit this fall on a ballot measure about marijuana legalization. A legalization ballot measure pending in Colorado specifically leaves the question to lawmakers.
Democratic Gov. John Hickenlooper added drugged driving to a list of measures he asked lawmakers to consider in the special legislative session expected to end Wednesday.
The White House Office of National Drug Control Policy has asked all states to adopt blood-limit, drugged driving laws and set a goal of reducing drugged driving in the United States 10 percent by the year 2015. But the White House doesn't tell states what nanogram limit to set for illegal drugs.
Law enforcement lobbyists in Colorado have vowed to keep trying to enact a pot DUI standard. Tom Raynes of the Colorado District Attorneys Council argues that even though medical marijuana is legal in Colorado, it's not dosed like prescription drugs and is easily abused.
"Folks don't know what they're taking," Raynes said. "It's like a doctor offering a bowl of drugs and saying, `Reach in, take what you think you need and go ahead and drive.' ... We've got to get a handle on this."
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