Driving towards a solution of "imprisoning more people" as punishment rather than other punishment have never succeeded. Many states already have first time drug offender and strike programs, people are already imprisoned over a weekend for things even as simple as misdemeanor possession until they can get a bail set. Rehabilitative forms of punishments such as severe fines, community service or mandatory classes and broadcasting them is much more effective in actually driving down rates of impaired drivers.

Whats more, police officers already have a wide authority of judgement when considering these factors around marijuana impairment currently. Relying on subjective evaluation from FST and physical presentation will only result in a higher rate of non impaired drivers being imprisoned.