The proposal targets “drugged driving” by setting blood concentration levels for five drugs: marijuana, cocaine, heroin, amphetamine and methamphetamine.
Bill sponsor Rep. William Rehm, R-Albuquerque, said his intent is to assist drugged-driving prosecutions.
The measure would establish a legal presumption that the driver is impaired by drug use, just as existing law makes it illegal to operate a vehicle with a blood-alcohol content of 0.08 percent or higher.
A retired Bernalillo County sheriff’s deputy, Rehm said existing law makes it all but impossible to prosecute someone for driving under the influence of drugs.
Field sobriety testing for drunken driving is simple and requires little officer training, he said. But officers need extensive training to become “drug recognition officers,” who can testify in court that a driver was impaired by drug use.
“As a result, there are few drug recognition officers in New Mexico, which defense attorneys require to testify about drug use and driving under the influence,” he said.
Opponents focus on the bill’s proposed limits on tetrahydrocannabinol, or THC, the main psychoactive component of marijuana.
While blood alcohol content provides measurable proof of intoxication, THC “is not necessarily indicative of behavioral impairment,” said Emily Kaltenbach, state director of the Drug Policy Alliance of New Mexico.
The group, which advocates for drug law reforms, has opposed the bill in previous legislative sessions, she said.
The measure puts the state’s 33,000 active medical cannabis patients at risk of arrest and criminal prosecution by setting THC limits that are unsupported by scientific research, Kaltenbach said.
The measure would make it illegal to drive with a THC level higher than 5 nanograms per milliliter of blood, based on a blood test done within three hours of operating a vehicle.
Colorado now uses the same 5-nanogram level to prosecute drivers for DUI, according to the Colorado Department of Transportation website.
Rep. Bill McCamley, D-Mesilla Park, said he plans to oppose Rehm’s bill.
“We need to be very careful that we’re not going to punish people who are not impaired when they are driving,” McCamley said. THC is unreliable as a marker for impaired driving, he said.
“If I use cannabis, I feel the effects for hours, but the active ingredient stays in my system for weeks, even though it is not affecting my senses at all,” he said.