Revise DUI laws to include controlled substances

This bill updates Montana's driving under the influence laws to explicitly include driving while impaired by controlled substances alongside alcohol. It directly affects all drivers in the state by expanding the definition of DUI to cover situations where a person is under the influence of alcohol and a controlled substance, as well as establishing specific THC blood concentration thresholds for marijuana impairment. The legislation creates new legal inferences for courts to use during trials, allowing blood alcohol levels of 0.08 or higher to be considered evidence of impairment, while maintaining the ability to present other evidence. Penalties for violations include fines ranging from $600 to $10,000 and jail time from 24 hours to one year, with stricter consequences for repeat offenders and those transporting passengers under 16.