House Bill 541 advanced on second reading after Representative Kelly described the measure as targeting a recent enforcement trend among Montana troopers: drivers who mix alcohol and illicit drugs before driving.

"The trend is the mixing of alcohol with illicit drugs and then driving," Representative Kelly said, adding that the Motor Vehicle Division and Montana Highway Patrol have reported rising incidents. Kelly told the committee the bill does not set a presumptive chemical threshold because of variability in combined substances; instead it requires officers to document driving behavior, observations of control, demeanor, and signs of impairment and then obtain the required tests.

Kelly said the bill carries a felony penalty as written to place convicted offenders into a compelled treatment program. The sponsor clarified the bill does not address mixing alcohol with prescribed medications or marijuana due to legal complexity.

There was no recorded floor amendment during the second‑reading sequence. The clerk recorded 65 yes and 35 no votes on the committee floor, and the bill passed second reading that day. The motion to recommend passage was made by Representative Kelly.