When it comes to driving or operating a motor vehicle under the influence, much of the focus is on alcohol. However, there are many other drugs that can also cause impairment. These substances are not limited to illicit drugs. There are a number of prescription and over-the-counter medications that are perfectly legal for you to take that could still impair your ability to drive.

The increasing prevalence of drugged driving poses challenges for safety advocates, researchers, policymakers and law enforcement. These challenges relate to raising awareness of safe drug use, establishing legal baselines and detecting impairment accurately.

Drugs used in combination

Drivers may use several different substances in combination with one another and/or with alcohol. The resultant effects on your brain can be unpredictable. Sometimes two drugs used in combination with one another can produce a synergistic effect. This means that the two or more substances amplify one another’s effects so that they are greater than what either would produce on its own.

Varied effects

Drugs can negatively impact more than one skill used in driving. Here are a few examples:

  • Decreasing your ability to divide your attention and perform multiple driving tasks at the same time
  • Affecting your coordination, decreasing your ability to control your vehicle through acceleration, braking and steering
  • Impairing your judgment, increasing your likelihood of taking dangerous, unnecessary risks while behind the wheel of a vehicle

Missing link to driver performance

Because the effects of different drugs can be so varied, there is not sufficient scientific evidence as yet to link certain blood concentrations of many drugs to driver performance the way there is with alcohol. Without the necessary information, there is no way to establish a legal limit for concentrations of these substances in the blood.

Research into these issues is ongoing and may eventually help to answer these challenges. However, scientific study is a slow, methodical process, and it may be some time before the necessary data is available on which to base meaningful changes.