It is no secret that powerful interests disapprove of legal marijuana. Therefore, I was skeptical of the research cited in the Colorado Springs Gazette editorial on marijuana and traffic safety (reprinted in the Portland Press Herald on Sept. 5).

I find it difficult to believe that making marijuana legal has increased, by a significant amount, the number of people who use it, or that because it is now legal, somehow that has made what is grown exponentially more intoxicating. My suspicion is there is a concerted effort to look for marijuana after an accident. If any THC is found, marijuana is automatically assigned blame. My concern is that the research is, in effect, creating a self-fulfilling prophecy for political ends.

The amount of time that THC remains in the body after ingestion has not been settled by science. It is claimed that trace amounts are detectable for up to 30 days after use. However, the period of acute intoxication, making it unsafe to drive, is unknown.

It seems to me that that is the crux of the issue. Law enforcement does not have a test to determine if someone is so impaired by marijuana that they are unsafe to drive. The alcohol field sobriety test is ineffective because marijuana and alcohol affect a person’s coordination differently. In other words, a stoned person may be able to walk a straight line but still be dangerously impaired. (Of course, that can also be said about a lot of over-the-counter cold medicines and whatnot.)

If the genuine concern is traffic safety, pushing marijuana back into the shadows will not help. Now that it is legal, hopefully, research will be undertaken to understand how marijuana affects the ability to drive safely and determine how long it takes to sober up after using.

Dan Phipps

Kennebunk