In Ohio and Nevada, where medical marijuana is legal, the limit for driving is two nanograms per milliliter of blood. In Washington state, that limit is five nanograms. A dozen other states, including Illinois, Iowa and Arizona, have zero-tolerance policies for driving under the influence of marijuana and various controlled substances.
In Colorado, both sides agree that people shouldn’t drive impaired; the fight is over what should be used as proof of impairment.
Marijuana advocates argue that, unlike with alcohol, traces of the drug remain in the bloodstream long after an individual has smoked pot, and that a THC test can mistakenly suggest a person is high, especially in a regular smoker who has built up tolerance to the drug. But officials who favor a blood-level limit say tests exist that can pinpoint “active” THC in the bloodstream in the hours immediately after marijuana usage.
People on both sides cite the work of Dutch researcher Jan Ramaekers, who found that marijuana users generally are impaired at a level of five nanograms, but that many cannabis users do develop higher tolerances.
Ramaekers, in an interview, said he supports the five-nanogram limit, noting that lawmakers have long set a legal limit for alcohol in the name of public safety, even though people have different tolerances and impairment varies by person.
“Who should the law serve: the individual or the population?” he asked.
Still, some in Colorado are concerned about drawing a bright line between impaired and unimpaired when it comes to marijuana. The state Senate’s majority leader, Democrat Morgan Carroll, said research suggests that impairment can occur with anywhere from two to 20 nanograms per milliliter of blood. “My number one problem is that you could convict someone at five nanograms who wasn’t actually impaired,” she said.
Lawmakers are working on a compromise to break the long-standing impasse. A bill backed by King and other legislators would set five nanograms as the legal limit, but a test indicating that level would not automatically result in a DUI conviction. Instead, people accused of driving under the influence would be able to argue in court that they weren’t impaired. The measure is working its way through the statehouse and appears likely to pass.
Carroll is still not fond of the five-nanogram limit but says she and others might be swayed by the provision that would allow defendants to make their case in court. “It gives the accused the opportunity to come in and offer proof,” she said.
At Tuesday’s hearing, a string of law enforcement officials and a state toxicologist testified in favor of the legislation. Ed Wood, whose son was killed in a car accident caused by a drugged driver, said he supported the bill but wants an even tougher standard. “We believe Colorado deserves better,” he said.
But Saurini and other wactivists voiced their opposition, with some arguing that marijuana often induces paranoia and causes people to drive abnormally slowly, as opposed to alcohol, which can provide the “liquid courage” to drive irresponsibly.
King, the lawmaker who has long pushed for a legal limit, grows agitated at the suggestion by some marijuana advocates that they drive as well or even better high. It’s a reason, he said, to put a limit in place as soon as possible.
“I heard that [argument] 25 years ago with alcohol,” he said. “If you want to smoke marijuana, smoke marijuana. But smoke and walk, smoke and get a ride, smoke and take a cab. Don’t smoke and drive — that’s the point we’re trying to make.”
Dennis reported from Washington.