It is common knowledge that alcohol and drugs affect driving. I have already posted a piece on how alcohol affects the body, so now let’s explore other types and how they hinder one’s ability to drive safely.
The use of illegal drugs or the misuse of prescription drugs—not unlike alcohol—makes driving unsafe and poses a significant risk to the driver, passengers, others on the road, and pedestrians.
According to the Centre for Addiction and Mental Health (CAMH), when we drive, our hands, eyes, and feet essentially control the vehicle while our brains control our hands, eyes, and feet. Safe driving requires alertness, good judgement, and the ability to make split-second decisions in response to a rapidly changing environment rife with many distractions. The introduction of alcohol and/or drugs into the body affects its normal functioning and impairs one’s ability to drive safely.
The extent of the problem
According to the 2016 National Survey on Drug Use and Health (NSDUH), 20.7 million people age 16 or older operated a motor vehicle while under the influence of alcohol that year while 11.8 million drove under the influence of illicit drugs. Additionally, men are more likely to drive while under the influence, as are a higher percentage of 18-to-25-year-olds.
It is difficult, however, to accurately measure how many automobile accidents are caused by driving while under the influence of drugs. This is due to many reasons including the lack of an effective test for drug levels in the body, that police don’t test for drugs if intoxicated drivers have an illegal blood alcohol concentration (BAC), and many motorists who are arrested for DWI have both alcohol and drugs in their system, making it difficult to determine which actually caused the dangerous driving.
In a 2009 National Highway Transportation Safety Administration (NHTSA) report, 18 percent of drivers killed in a vehicular crash tested positive for at least one drug while a 2010 study demonstrated that 11 percent of deadly accidents involved a drugged driver. This data underscore the severity of the problem and the need for additional attention.
How drugs impact one’s ability to drive safely
Depressants slow down one’s body and brain. Depressants—including alcohol, prescription sedatives and painkillers, some cold or allergy medications, certain cough remedies, and opiates like heroin—reduce one’s alertness and impair one’s motor skills and coordination. Depressants also blur or double one’s vision and affects depth perception, making it difficult to safely gauge the distance between other vehicles or people. Finally, depressants cause drowsiness and dizziness which can lead to dangerous driving.
Alcohol, in particular, is notorious for leading people to overestimate their confidence and, consequently, not recognize diminished driving skills. Thus, when one drives under the influence of alcohol, s/he often speeds, weaves, fails to stay in one lane, and, in many cases, crashes.
When alcohol is mixed with other depressants, a synergistic effect results in that the combination of the two is more dangerous and intense than either drug by itself.
Stimulants—as their name suggests—stimulate the central nervous system and brain. Stimulant drugs include amphetamines and cocaine, as well as caffeine and some diet pills. Whereas these substances increase alertness, this does not necessarily equate to improved driving skills. In fact, stimulants have been linked to increased aggression and hostility behind the wheel, hallucinations, affected hearing, and impaired vision including “snow lights” (peripheral flashes or light movement).
Of particular concern is that the stimulant effect can wear off without a moment’s notice, thus resulting in immediate fatigue and increased driving risk.
Cannabis impairs attention span, concentration, reaction time, muscle strength, depth perception, and hand steadiness—all of which can negatively impact one’s ability to drive. This is particularly problematic given the legalization of marijuana in many states and pushes to increase legalization efforts in others, including Minnesota.
Hallucinogens include ecstasy, mescaline, psilocybin, and LSD. These drugs distort one’s mood and perceptions, thus increasing risky driving and associated dangers.
The bottom line
Not only is drunk driving dangerous, but operating a motor vehicle under the influence of drugs can be equally problematic. Depending on the drug, different effects on the body ensue. Because there is no standard to accurately assess these effects’ actual impact on driving, it is difficult to determine a specific level of impairment to justify creating any type of standardized test or BAC level or enacting appropriate legislation like current DWI alcohol laws. Whereas identification of drugs in a motorist’s system while driving or following an accident may provide proof beyond a reasonable doubt to sustain a conviction for DWI, in order to enact appropriate legislation, additional research on these effects—and subsequent legislative action—is necessary.