An argument regularly raised by those who want to keep marijuana illegal is that because there is no equivalent of a breathalyzer test for marijuana intoxication, DUI laws would be impossible to enforce. The California Supreme Court just shot a very large hole in that argument.
It’s an odd argument anyway, given that tens of millions of Americans regularly take drugs that can impair driving — pain relievers, antihistamines, etc. — for which there is no simple, roadside test. For most of these drugs, and for marijuana, the old-fashioned field sobriety test works quite well.
Still, people have tended to regard the alcohol breath test as the gold standard. Now, the California Supreme Court has ruled unanimously that defendants can challenge the accuracy of these tests. As the Los Angeles Times reported, “Even though experts say the standard ratio used to derive a blood-alcohol concentration from breath generally approximates or even underestimates the amount of alcohol the driver consumed, they also agree that Breathalyzer results may sometimes overestimate the amount of alcohol in the blood.”
No one — repeat, no one — should ever drive while impaired by anything. But it’s time to put aside the false notion that Breathalyzer tests are infallible, or that there’s no way to enforce laws against driving under the influence of marijuana.