(Joe Amon, Denver Post file)

Stoned driving stoking quite the debate in California over setting a legal limit

Determining when a motorist is too stoned to drive isn't as easy as it sounds

SAN JOSE, Calif. — Growing acceptance of medical marijuana and an initiative to legalize recreational pot use in California are stoking a debate over how to keep stoned drivers off the roads.

While driving under the influence of marijuana is illegal in all 50 states, determining when a motorist is too stoned to drive isn’t as easy as it sounds. Unlike alcohol, the active ingredient in marijuana can linger in the body long after any noticeable effects of the drug wear off.

In 12 states, driving with any trace of marijuana in the body is a criminal offense, and in five others, the presence of a designated amount of marijuana’s active ingredient in a driver’s blood triggers an automatic conviction.

But California doesn’t have a legal limit. As a result, prosecutors complain it can be difficult to convince a jury to convict a driver based on observations by witnesses or police, along with blood-level results that aren’t set in stone.

Santa Clara County District Attorney Jeff Rosen is sponsoring a controversial bill to create a California standard. He believes the bill strikes a reasonable balance by requiring evidence of impairment along with confirmation of marijuana ingredients in the driver’s blood. It more closely resembles a law adopted in Colorado, one of four states that has legalized recreational marijuana in the past four years, rather than laws in states where firm legal limits or zero-tolerance policies trigger a likely conviction.

“No rational person would dispute that driving under the influence of marijuana is dangerous,” said Rosen, who proposed the bill being carried by Campbell Democrat Evan Low and Palmdale Republican Tom Lackey. “This is an important public safety measure.”

Not everyone agrees, including Santa Clara County Public Defender Molly O’Neal.

“Traffic violations have historically disproportionately impacted people of color and the poor,” she said, “and have served to capture them in a system of fines and fees from which they cannot escape.”

Researchers on both sides of the issue have mounds of evidence suggesting that legal-limit laws either are the best solution or that they go too far.

“The data are incomplete,” said Dr. Igor Grant, chair of the psychiatry department at UC San Diego and director of its Center for Medicinal Cannabis Research, which was awarded $1.8 million by the Legislature to develop a field test for marijuana intoxication. “I think we need to have full medical evidence as to whether that’s the correct standard or not if we are going to prosecute people.”

It’s an issue the entire country is grappling with. By next year, recreational marijuana is likely to be legal in a quarter of the nation, and medicinal use is already legal in about half the states. Recent polls show recreational marijuana initiatives headed for the November ballot leading in California, Maine, Michigan and Massachusetts.

The American Automobile Association’s traffic safety foundation recently released a study of arrest data, which concluded that it is impossible to accurately determine marijuana impairment from a blood-level test. However, in second study, the foundation reported that the share of drivers in Washington who had recently used marijuana and were involved in fatal crashes more than doubled in 2013 to 17 percent after the state legalized pot in 2012. In Colorado, which has a population one-seventh the size of California’s and where recreational pot is legal, state highway patrol officers last year arrested 665 drivers who had marijuana in their systems, compared with 674 in 2014. (California does not currently track how many people are arrested or prosecuted annually on suspicion of driving under the influence of cannabis.)

The AAA foundation recommends that states replace blood tests like the one in the Rosen bill and instead rely on a combination of police officers trained to detect signs of impairment, such as eyelid tremor, backed up by a test for the presence of tetrahydrocannabinol, or THC, the psychoactive ingredient in marijuana. California lawmakers also are considering a Senate bill along those lines. SB 1462 would allow police to use a preliminary roadside saliva test to establish reasonable cause to believe a driver is stoned, but the test could not be used in court as proof.

The bill proposed by Rosen and carried by Low and Lackey, AB 2740, would set a legal limit on THC of 5 nanograms per milliliter, require corroborating evidence of impairment, and carry significant penalties similar to drunken driving, including a six-month driver’s license suspension and possible jail time or service on a freeway work crew. Washington, Colorado and Montana use the same legal limit, while Pennsylvania, Nevada and Ohio have set lower thresholds. Some researchers say drivers can be significantly impaired at 5 nanograms, but others say that may not be the case, especially for frequent users.

Previous efforts in the past four years to pass similar bills died in committee. The current attempt to set a legal limit was recently approved by the Assembly public safety committee after Rosen and internationally known cannabis researcher Marilyn Huestis, who recently retired from the National Institute on Drug Abuse, testified.

“This bill is absolutely going to reduce the number of people killed and seriously injured,” Huestis said in a phone interview.

Rosen, one of only a few district attorneys to support initiatives that softened some of the state’s strict sentencing laws for nonviolent offenders, spent about $6,000 of his county budget to fly Huestis in. The National Organization for the Reform of Marijuana Laws, which opposes the bill, criticized the public expense, but the Rosen administration defended the cost as for the public good.

The day after the hearing, a company trying to develop a marijuana breathalyzer test announced that Huestis had agreed to serve as a scientific adviser, prompting NORML to claim her testimony was compromised by a conflict of interest that she failed to divulge to the committee. Rosen’s office said they were not aware of her affiliation with Cannibix but added it wouldn’t have made a difference. In a phone interview, Huestis said the advisory role had no influence on her opinion, which was formed after decades of research.

Currently, the bill is under review by the Assembly appropriations committee, which will decide May 27 whether to allow it to move ahead.

Low acknowledged that passing the bill may prove challenging, partly because some of his colleagues contend that doing so before the UC San Diego study is finished in three years would be “putting the cart before the horse.”

But the Rosen administration contends the state needs to try to deter drugged driving now by setting a legal limit. Lackey, a retired CHP officer, also defended the need for a bill, saying driving while high will prove to be a bigger problem than people think.

“It’s kind of like alcohol and drunken driving was in the ’70s and 80,” he said, “when it wasn’t taken seriously.”

The Associated Press contributed to this story. Contact Tracey Kaplan at 408-278-3482. Follow her at Twitter.com/tkaplanreport.

This story was first published on MercuryNews.com