Drugged driving is a major public health concern. It puts the driver at risk as well as other individuals who are sharing the road. The main concern of driving while under the influence of drugs is that any drug that works by acting on the brain could ultimately impair the driver’s judgment, reaction time, and motor skills which may cause an auto accident.
Drugged driving is hazardous because drugs can act on the brain by altering cognition, attention, coordination, perception, balance, and other skills needed for safe driving. The effects of different drugs will differ depending on how much has been consumed, the user’s drug use history, their mechanism of action, and other factors. Marijuana, for example, affects the portion of the brain that is responsible for controlling the body’s movements, memory, coordination, balance, and judgment. These effects are typically multifaceted, so more research is needed in order to determine the exact impact of the drug on the driver’s ability to react to unpredictable and complex situations. However, the following information is known:
- Evidence from simulated and real driving studies has indicated that marijuana can have a negative effect on the attentiveness of a driver as well as perception of speed and time. Their ability to recall information from previous driving experiences is also affected.
- An analysis of around 60 studies, including on-road experiments, driving simulators, and labs, has indicated that cognitive and behavioral skills that are related to driving were impaired when THC blood levels were increased.
- A study using over 3,000 drivers who were fatally injured in Australia indicated that when THC was present in a driver’s blood, he or she would be considerably more likely to be the cause of a road accident.
- Research has shown that the level of a driver’s impairment increased substantially when alcohol was combined with marijuana use.