U.S. studies show that driving under the influence of drugs causes more fatal crashes than alcohol related drunk driving. Data reported to the National Highway Transportation Safety Administration (NHTSA) showed forty-three percent of drivers tested in fatal crashes in 2015 had used a drug while 37 percent showed alcohol levels above a legal limit. Drivers killed in crashes who tested positive for drugs showed that 36.5 percent had used marijuana and 9.3 percent used amphetamines.
The study included any substance that can impair driving, including prescription medications, over-the-counter medicines and illegal drugs. Previously in 2013 alcohol related accidents without drugs topped alcohol and drug- related traffic fatalities. The opioid epidemic and legalized marijuana may increase drug related fatalities. In Colorado, marijuana-related deaths increased by 48 percent after the state legalized recreational use of the drug. Since marijuana can linger in the body for weeks this study may not be accurate. New laws starting in 2018 for California make it illegal to smoke or ingest pot while driving or riding in a car.
Drivers on prescription drugs are becoming a greater problem for law enforcement. The behavioral effects of prescription medication vary widely, depending not just on the drug but on the person taking it. Some drugs, like anti-anxiety drugs, can dull alertness and cause a slower reaction time, while others, like stimulants, can encourage risk-taking and hurt the ability to judge speed and distances. Taking prescription drugs with alcohol can cause serious driving impairment.
Last year, Tiger Woods was found asleep in his damaged car on the side of the road and was arrested by the Florida Police. Tests revealed he had no alcohol in his system. In his public apology, Woods blamed his impairment on "an unexpected reaction to prescribed medications."
Unlike alcohol, there is no agreement on what level of drugs in the blood impairs driving. Law enforcement officers are undertaking special training to spot signs of drug impairment and are making arrests for suspected driving while under a drug that is illegal or legal.