Voters last month in California, Maine, Nevada and Massachusetts agreed to legalize marijuana for recreation, bringing the total to eight. But even those who support legalization recognize there is a possible threat to public safety on our roads. So that raises the question: How can you tell if someone is actually impaired by marijuana?
Answering this question has proven much more thorny than determining who is drunk. That has prompted some states to adopt measures that arbitrarily assign certain amounts in the blood as being an indicator of impairment. The problem is, these measures aren’t accurate. That means innocent people are being locked up and facing criminal and civil consequences when they have not done anything wrong. It could also mean that in some instances, drivers who really were impaired are getting away with it.
The problem is that in legally treating marijuana like alcohol, states have forgotten that the human body doesn’t treat the two substances the same way. Alcohol moves through the human body quickly. The effects of alcohol are based on a person’s weight and size, their metabolic rate, their food intake and how much alcohol has been consumed. Still, generally speaking, the more you drink, the more drunk you are going to be, which means the worse your driving will be. This is generally true no matter what your size or no matter how often you drink. The same is not true for those who consume marijuana because the drug stays in your system for much longer. A higher concentration of THC in one’s system is not necessarily an indicator of intoxication. Rather, it is generally an indicator that someone is a regular user of the drug, but not that they are currently under the influence. Continue reading