Driving While High a Still-Hazy Issue

Driving while under the influence isn’t just for drunks anymore.

There’s a largely unrecognized group causing a growing number of accidents — minor and fatal — across the country: drugged drivers. And many of them may be causing accidents with their use of pot.

New data from the National Highway Traffic Safety Administration says legal and illegal drugs are impairing 16.3 percent of nighttime drivers nationwide, and half of those are using marijuana, according to the LA Times.

“Marijuana is a significant and important contributing factor in a growing number of fatal accidents,” White House director of National Drug Control Policy Gil Kerlikowske told the Times. “There is no question, not only from the data but from what I have heard in my career as a law enforcement officer.”

In California law enforcement points to relaxed marijuana laws and fast-growing use of medical marijuana. But even as legal use in other states rises — Connecticut became the most recent to decriminalize smaller amounts in June — many have yet to develop coherent enforcement directives about driving while under the influence of pot.

Zero-tolerance rules exist in 13 States, but most others, including California, rely merely on law enforcement’s general guidelines for determining impairment, reportedly making convictions more difficult to obtain.

Part of the problem with establishing a metric for unacceptable levels of the drug in drivers resides in a lack of relative consensus about the drug’s impact, and how long it may or may not last.

"To have a law that says above a certain level you are impaired is not scientifically supportable,” toxicologist Sarah Kerrigan told the Times. “I don't think police need the tool, but my opinion may be in the minority."

While the drug can remain in a user’s system for weeks, many say that its effects are gone in a matter of hours. And while studies of alcohol use and impairment have been conducted for decades, there has been far less research of marijuana impairment. With the growing debate on — and number of — marijuana users on the road however, a healthy crop of studies on that very topic is expected.