MONTPELIER — Vermont’s preparations for a retail marijuana market are now focused on what’s been a point of contention for several years – ensuring law enforcement has the tools needed to identify impaired drivers on the road.

Vermont’s Cannabis Control Board took up the topic at their meeting Thursday morning, with Vermont State Police Sgt. Jay Riggen offering his thoughts. Board member Brian Pepper described him as ‘Vermont’s leading expert’ when it comes to impaired driving.

There’s no marijuana equivalent of a breathalyzer test, so the process after someone is pulled over and suspected of being under the influence becomes more complicated.

“Two cardinal sins can be made,” Sgt. Riggen said. “One is we take somebody into custody who isn’t impaired, but worse is we release somebody roadside who is impaired and let them keep driving.”

You might think a roadside saliva test for marijuana would be an easy way to determine whether someone is under the influence behind the wheel, but according to the National Institute on Drug Abuse, it can be found in saliva for days or even weeks after use.

Sgt. Riggen said relying on that as a first means to determine a driver’s sobriety has some obvious pitfalls.

“They’re positive on a cannabis test – ‘Oh, everything I see means they’re impaired by cannabis,’ that’s devastating,” Sgt. Riggen said. “If it ever were to be a thing, it would be at the end of a process when the officer has already observed certain signs or symptoms of impairment and wonders what the cause is.”

That means a lot of the work falls to drug recognition experts, or D.R.E.s. Riggen said they average a 92 percent success rate in field tests, but the issue is that some parts of the state like the Northeast Kingdom have fewer DREs nearby.

James Pepper of the Cannabis Control Board explained why a quick response time is critical.

“The response time can be an hour plus, and that’s vital time when you think about your body metabolizing whatever substance might be impairing it, but also if someone is having a medical condition,” Pepper said. “If they got a concussion after their accident and it’s mimicking impairment, you don’t want unnecessary delays because folks are waiting for a DRE to arrive on the scene.”

Roadside saliva tests could be used to rule out marijuana impairment and allow those suffering a medical condition to get attention quicker. As part of the retail bill passed last year, officers will need to get a warrant before conducting the test.