New Times Inquiries Spark Change in How Arizona Investigates Drivers Suspected of Pot Use

Questions by New Times about statistics related to marijuana and driving have caused Arizona officials to make changes to state traffic-accident reports.

New checkboxes referencing marijuana will be added to accident forms, possibly as soon as next year, says Alberto Gutier, director of the Arizona Governor's Office of Highway Safety. One box will show if an officer has a "suspicion of THC" impairment by a driver while another box will show if there's evidence a driver has a medical-marijuana card. Gutier says top police officials and prosecutors think the change is a good idea.

In several interviews with Gutier, New Times had asked why the state wasn't gathering more information about the possible influence of marijuana on highway safety. State accident forms, in the category of "conditions influencing driver," currently contain checkboxes that include suspicion of the use of alcohol, illegal drugs, and prescription drugs. However, more than 80,000 people in Arizona legally use cannabis under the state's 2010 Medical Marijuana Act. For them, marijuana is neither an illegal nor a prescription drug.


On a larger scale, as New Times' cover article last week details, the pace of data-gathering on this issue simply has not kept up with the nationwide rise of legal and decriminalized marijuana. Nearly half the states and Washington, D.C., have legalized marijuana for general adult use or medicinal purposes. In Colorado, Washington, and Oregon, all adults 21 and older now have the freedom to buy cannabis products at state-regulated retail stores. Efforts are under way to bring recreational-use laws to nine states next year, including Arizona, where a proposed ballot initiative reportedly now has picked up more than 100,000 signatures. But data remains limited about the alleged harms of marijuana in this age of increased tolerance.

The lack of evidence hasn't stopped pot prohibitionists from predicting carnage on America's highway from legalization.

In statements to the press and public, anti-cannabis activists including Tom Gorman of the Rocky Mountain High Intensity Drug Trafficking Area and Yavapai County Attorney Sheila Polk have emphasized the results of studies in Colorado and Washington which showed a doubling in the last two years of THC-positive drivers involved in fatal accidents. They'd like the public to believe the statistic means that more pot users are causing crashes.

However, officials in those states admit they have no idea whether those drivers were culpable in the crashes, much less whether the drivers were actually impaired by THC, the main psychoactive component in the cannabis plant. Most of the blood samples in the Colorado and Washington studies were taken from deceased drivers and indicated only the presence of THC or its metabolites, which are known to remain in the body days or weeks since the user last consumed. 

In Arizona, Colorado, Washington, and other states, officials have no idea how many crashes are caused by people suspected of impairment from marijuana. No matter what you've heard, the experts still don't know whether drivers impaired by pot have caused more — or perhaps fewer — traffic collisions in recent years.

Part of the problem has been that the states don't track the data like they do with alcohol-related crashes. With the new checkboxes on the accident forms, Arizona can finally begin tracking the number of times that officers investigating crashes believe that marijuana — the second most used impairing substance behind alcohol — may have played a role.

Police across the state feed their accident statistics to the Arizona Department of Transportation, which compiles an annual crash-facts report. (Note: The "Driver Physical Condition" part of the 2014 Crash-Facts report can be found on page 31.) Stats on driving and impairment also can be used to obtain federal grants.

"We'll do our best to get to the bottom of things," says Gutier. "The data is important to me."

New Times research from 2013 shows that marijuana-impaired drivers cause relatively few crashes compared to drivers impaired by booze or other drugs. A review of toxicology reports from police agencies in Phoenix, Scottsdale, and Chandler, plus the state Department of Public Safety, showed that drivers investigated for causing crashes who were later found with only THC in their systems made up only about 1 percent of suspected impaired drivers.

For the past couple of years, New Times has asked officials in Colorado about the lack of marijuana checkboxes on its accident reports. Glenn Davis, Colorado highway safety manager, says his state's form probably will be revised next year, too. Adding marijuana checkboxes had been previously discussed in a committee he's on, he says.

"We owe it to ourselves to start getting that data," Davis says. "I'm going to advocate for it."

The subject of impaired driving will continue to play an important role in the ongoing national debate about marijuana, and the new data collected in Arizona or elsewhere will be mere pieces of the overall puzzle. Experts still don't know how much marijuana it takes to impair a driver, but research suggests that the level may be remarkably different for different people, unlike alcohol.

Staci Hoffman, a research analyst with the Washington State Traffic Commission, says that while studies have shown that it's only a matter of time before alcoholics get into a crash, the same can't be said of marijuana users. The lack of good data is one reason for the uncertainty, but so is the variable effect of marijuana, which also doesn't affect judgment in the same way as alcohol.

The state driving limit for marijuana in Washington is five nanograms, the same as in Colorado. But a spokesman for the Washington State Patrol told New Times in 2013 that no one really knows whether all marijuana users are impaired at 5 nanograms.

The Arizona Supreme Court last week tossed out the state's draconian zero-tolerance law for medical-marijuana users, ruling that authorized patients could raise lack of impairment as a defense against a DUI prosecution, which they previously could not do.