Laws should be passed in order to rectify or prevent some form of wrongdoing that has been proven to be a problem in the world. Additionally, those laws should specify a feasible way for police to detect the crime, minimize the ability of police to abuse their powers while enforcing the law, and set out penalties that fit the crime.
In this sense, Georgia's laws that prohibit driving under the influence (DUI) are not very good. While drunk drivers have been shown to be a problem on the roads, setting a strict per se legal limit of 0.08% blood alcohol content (BAC) is a poor way to enforce the law. Allowing police to arrest drivers who are below this limit, anyway, gives them far too much discretion. Finally, the penalties for DUI convictions are notoriously strict.
And when our state's DUI laws are applied to drugged driving, the laws become close to absurd.
The Fool's Errand of Accurately Detecting Drugged Drivers
The true difficulties of Georgia's drugged driving laws lie with the inability to efficiently and accurately detect whether someone is under the influence of drugs during a traffic stop. According to the Governors Highway Safety Association, there are no fewer than 430 different drugs or metabolites in the national highway safety database. Each one of these substances could, in theory, impair someone's ability to drive, but many of them will create different kinds of impairments. However, detecting the presence of any of these drugs in the short course of a traffic stop – completely isolated from complex chemical equipment – is impossible.
Police Given Too Much Discretion
Without the ability to accurately and scientifically detect the presence of a drug in a DUI suspect's system, the law falls on the shoulders of police – it is up to them to determine if someone is “impaired.” Unfortunately, police only interact with DUI suspects for the short moments of a traffic stop – your eccentricities or simple nervousness could be interpreted as “visual impairment by drugs.”
In essence, without testing equipment, it is up to police to determine who is under the influence of drugs. This gives police way too much power.
Conflicting Evidence on Whether Drugs are a Problem for Drivers
Finally, there is not even a consensus that some drugs are a problem for drivers.
For example, two studies on the impact of marijuana on drivers seem to have come to contradictory conclusions. In one, the Insurance Institute for Highway Safety found that insurance claims related to car accidents rose by 3% in states that had just legalized marijuana. Another study published in the American Journal of Public Health, though, compared the number of fatalities from car accidents in Washington and Colorado from before and after they legalized marijuana; the study found no significant change.
Without conclusive evidence that driving after smoking marijuana is dangerous, we might be severely misallocating the resources of law enforcement in a way that does not benefit society.