House Committee Advances Cannabis Impairment Testing Standards Bill

The House Transportation and Infrastructure Committee voted 61-2 on Thursday to advance legislation requiring federal officials to develop evidence-based standards for detecting cannabis impairment in drivers.

The provision is embedded in the Building Unrivaled Infrastructure and Long-term Development (BUILD) for America's Act, a sweeping transportation bill that now heads to the full House. The near-unanimous vote signals bipartisan recognition that cannabis legalization has outpaced the science of roadside impairment testing.

Unlike alcohol, where blood alcohol concentration provides a clear legal threshold, cannabis metabolites can remain in a person's system long after psychoactive effects have worn off. Current field sobriety tests and drug recognition expert evaluations remain subjective, creating legal gray areas in states where marijuana is legal.

What the Bill Requires

The legislation directs the Department of Transportation and other federal agencies to conduct comprehensive research on drugged driving, with specific focus on marijuana. The study would need to assess current detection methods, evaluate their accuracy, and propose standardized protocols that could be adopted nationwide.

This marks a shift from previous federal approaches, which largely punted on the impairment question while marijuana remained Schedule I. With 24 states now allowing adult-use cannabis and 38 permitting medical marijuana, law enforcement agencies have been clamoring for better tools.

The bill doesn't propose specific THC blood concentration limits—a contentious issue in state legislatures. Colorado's 5-nanogram per milliliter threshold, for instance, has been criticized by researchers who say THC levels don't correlate reliably with impairment the way BAC does for alcohol.

Industry and Advocacy Response

Cannabis industry groups have long argued that arbitrary THC limits unfairly penalize medical patients and regular consumers who may test positive despite being sober. Several companies are developing alternative impairment detection technologies, from eye-tracking devices to cognitive testing apps, hoping to crack a problem that's vexed toxicologists for years.

Law enforcement organizations, meanwhile, have pushed for any standard that gives officers clearer guidance. The current patchwork—where some states have per se limits, others use zero tolerance, and still others rely entirely on officer discretion—creates confusion for prosecutors and defense attorneys alike.

The two committee members who voted against the broader BUILD Act did so over unrelated infrastructure spending provisions, not the cannabis testing language.

What Happens Next

The bill's path through the full House remains uncertain, though transportation legislation typically enjoys broad support. If enacted, federal agencies would likely have 18-24 months to complete the study and deliver recommendations to Congress.

Several states aren't waiting for federal guidance. Washington is piloting saliva testing devices, while Massachusetts recently funded research into cognitive impairment benchmarks that don't rely on THC measurements at all.

The National Highway Traffic Safety Administration has already begun preliminary work on the issue, but lacks a congressional mandate or dedicated funding. This legislation would change that, potentially accelerating the timeline for national standards.

For cannabis businesses, particularly those in delivery and transportation, clearer impairment standards could reduce liability concerns and help establish workplace safety protocols. The current ambiguity makes it difficult for employers to craft defensible drug policies that distinguish between off-duty use and on-the-job impairment.

The BUILD Act also includes provisions for electric vehicle infrastructure and freight corridor improvements, making it a priority bill for House leadership this session.

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This article is based on original reporting by www.marijuanamoment.net.