Safety group head calls for 'drugged driving' standards, tests

As more states legalize marijuana, the unknown risk of “drugged driving” persists, the head of the National Safety Council, a U.S. organization that advocates for better safety measures, said Wednesday.

Medical marijuana is legal in 25 states. Both medical and recreational uses are accepted in four of those states and Washington, D.C.

National Safety Council CEO Deborah Hersman said the problem with legalization is a lack of follow-up in identifying legislation related to when people shouldn’t use the drug, say when driving. She said the question after that becomes, “What constitutes impairment behind the wheel?”

While states have laws that define what constitutes drunken driving and how to test for it, they lack similar definitions and testing procedures for driving under the influence of marijuana.

‘Arbitrary’ 0.08%

“As you know, for alcohol, we have this longstanding position that [a blood alcohol content level of] .08 [percent] is the limit, but it wasn’t always .08,” Hersman told Automotive News, noting that the limit has decreased significantly over the past 30 years. It previously was 0.15 percent, then 0.1 percent.

“The [definition of] ‘what constitutes legal impairment’ is really, fairly arbitrary,” she said. “It’s a negotiated number of what, politically, can get passed.”

Matt Abel, a criminal defense attorney at Cannabis Counsel, of Detroit, agreed that a national standard would be arbitrary. “No such standard is possible,” he said.

He referred to a study submitted by the AAA Foundation for Traffic Safety in May that said that while fatal crashes in the state of Washington involving marijuana use leapt to 17 percent of all fatal crashes in 2014 from 8 percent in 2013, establishing legal limits for THC levels can’t be supported by science. Washington state legalized marijuana at the end of 2012.

Jury trials

“I think it’s possible that people can be impaired by cannabis and unable to do all kinds of things, but not everyone is impaired by cannabis,” Abel said.

Testing for THC levels is worthless, he said, if the levels can’t be linked to impairment -- especially when people react so differently to the chemical. Instead, a field sobriety stand, walk and turn test would be better suited, Abel said. As long as the physical tests are recorded with police body or dashboard cameras, he added, a jury can appropriately decide whether or not a person was fit to drive.

Hersman said tests for levels of THC [tetrahydrocannabinol] -- the ingredient in marijuana’s responsible for most of its psychological effects -- are not widely marketed, but her group advocates for oral fluid testing, which would be a swipe of the mouth on the roadside.

Nationwide standard

Hersman said she stands by unifying the states under one preventative standard, adding that the National Highway Traffic Safety Administration could serve an important role in leading the way in tests and limits.

While some studies, such as the AAA one, found an increase in crashes involving marijuana use, a 2015 study by NHTSA found that demographic factors such as age and gender appear to contribute to an increased crash risk, not marijuana use.

NHTSA did not immediately return calls seeking comment.