Marijuana and Its Effects on Driving

Table of Contents


Marijuana, also known as cannabis, is a drug that is commonly used for both medicinal and recreational purposes. Its use has been legal in some states, while in others it remains illegal. With the increasing legalization of marijuana in some states, it is important to understand the potential effects of the drug on driving.

How marijuana affects the body

A. Short-term effects When someone smokes or ingests marijuana, the main psychoactive ingredient, tetrahydrocannabinol (THC), rapidly enters the bloodstream and is carried to the brain. The effects of marijuana can be felt within minutes and can last for several hours. Short-term effects include impaired memory and concentration, distorted perception, and difficulty with problem-solving and coordination.

B. Long-term effects Long-term marijuana use can lead to addiction, which can lead to withdrawal symptoms such as irritability and difficulty sleeping when the drug is not used. Regular use of marijuana can also cause respiratory problems, such as chronic bronchitis. Long-term effects on cognitive function are also a concern, particularly in youth, whose brains are still developing. Regular marijuana use can also lead to reduced attention and verbal memory.

Effects on driving

A. Reaction time Marijuana can slow reaction time, making it difficult to respond quickly to unexpected events on the road. This can increase the risk of a crash.

B. Coordination Marijuana can impair coordination, making it difficult to control the vehicle, especially when making turns or changing lanes.

C. Judgement Marijuana can impair judgement, making it difficult to make decisions or react to changing road conditions. This can make it difficult to react to traffic signals and road signs.

D. Tracking and spatial perception Marijuana can affect tracking and spatial perception, making it difficult to stay in a lane or judge the distance between vehicles. This can also make it difficult to judge the speed of other vehicles.

Laws and statistics

A. Laws regarding marijuana and driving Laws regarding marijuana and driving vary by state. In states where marijuana is legal, it is illegal to drive under the influence of marijuana. The legal limit for THC in the bloodstream is 5 nanograms per milliliter of blood in some states. However, many states have zero tolerance laws for drivers under 21 years old.

B. Statistics on marijuana-impaired driving According to the National Highway Traffic Safety Administration, the number of drivers involved in fatal crashes who tested positive for marijuana has increased in recent years. In 2019, there were more than 12 million self-reported instances of drunk driving and about 2.3 million self-reported instances of drugged driving, marijuana being one of the commonly cited drug.

It is important to note that the relationship between marijuana use and crash risk is complex, and more research is needed to understand the relationship between the two. The effects of marijuana can vary widely depending on factors such as the dose, method of administration, and individual characteristics.


Marijuana can have significant effects on driving, including slowing reaction time, impairing coordination, judgement, and tracking and spatial perception. These effects can increase

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