The problem that MANY PEOPLE have is that they cannot discern the difference between the two topics:
- what does an intoxicant do to the physiology of the human body?
- what does an intoxicant do to the personality of a human being?
The two are often conflated, and they should not be. Auto accidents are often a culmination of multiple inputs, resulting in a bad output. Vehicle speed, vehicle condition, environmental conditions, human abilities (or lack thereof), human emotion, etc .... These all play into an auto accident. So this is sort of a mathematical equation ... A x B x C x D ... = output. The more inputs, or the greater the magnitude of the inputs, the larger the result. Simply put, angry/aggressive people get into more accidents because of their personality, not their physiology. When their personality is multiplied by alcohol, it has a propensity to increase the likelihood of having an accident. It's not against the law to be grumpy; but it is against the law to be intoxicated behind the wheel.
What alcohol does the human body in terms of physiology is well known, well studied, and accepted legal evidence.
Read this document for a good understanding of the effects of alcohol on humans and auto accidents:
https://ndaa.org/wp-content/uploads/Alcohol-Toxicology.pdf
We know exactly how quickly alcohol enters and exits the human system. The absorption and desorption rates are very consistent, easily tested and legally credible in terms of evidentiary admissibility.
The thing about THC (marijuana) is that there is no large-sample data to show how it affects human physiology; nothing that is accepted by any credible sources such as the FDA, DEA, NHTSA, NIH, etc ... No credible studies have yet shown how THC is the causation of degradation of the human condition ...
- how should THC be quantified in terms of intoxication?
- at what level of THC as a % of quantification does it affect human abilities (both cognitive and physical impairments)
- can THC be "normalized" (standardized) so that in some measure of X units, it can be predicted that Y level of intoxication will result?
What intoxicants do to the body are a different topic than what they do to a personality. DO NOT CONFUSE THE TWO TOPICS.