The dangers of driving under the influence of illegal and prescription drugs are well known. Despite these risks, millions of Americans still drive while under the influence of drugs. According to the most recent National Survey on Drug Use and Health in 2013, almost 10 million Americans admitted to driving under the influence of illegal drugs.
Different drugs can have different impacts on a person's driving ability. For instance, marijuana and certain pain medications can impair reaction times. Stimulants, such as cocaine and methamphetamine, will alter a driver's mood, making him or her more likely to engage in risky or aggressive driving.
Unlike with alcohol, there are not yet tests that reliably measure the impact of drugs in a person's system. Oftentimes impaired drivers have both alcohol and drugs in their system at the time of their arrest. For these and other reasons, it can be difficult to measure the exact impact of driving while under the influence of drugs.