Marijuana and alcohol, when used together, can make a person truly dangerous on the road. These two substances work together to intensify the effects of one another, which can make driving extremely risky. However, even when marijuana is used alone, it can cause an individual to experience serious effects that will affect their driving ability and even make a fatality more likely to occur.
For example, there has been an increase in the number of auto-related deaths caused by individuals with only marijuana in their systems in the state of Colorado. In 2014, 52 percent of drivers involved in fatal accidents were found to have no trace of alcohol in their system. In 2016, this number increased to 69 percent. Drivers under the influence of marijuana caused at least some of these fatalities, and because the state recently legalized the use of this drug, the increase seems likely to be associated with marijuana.
Marijuana, even when used on its own, can cause a driver to do things that could be dangerous. Many individuals driving under the influence of marijuana drive slower than they should, drive erratically, drift between lanes, and have diminished reaction times. Some strains of the drug are also extremely potent, which can cause people who are high to hallucinate or experience psychosis. This can cause serious problems for one attempting to drive a car. In addition, drivers who have THC in their blood are actually twice as likely to become involved in a fatal driving accident than those who are completely sober.