It’s the holiday season, and a lot of people will be on the roads and in our cars. As medical marijuana laws have become more relaxed across the country, people want to know what is happening to drivers who use cannabis. How can we be safe, and how does cannabis compare to other substances that are legal such as alcohol and benzodiazepines?
A lot of people think cannabis doesn’t impair driving, but it does. Cannabis reduces your ability to make decisions as a driver. So, it’s not entirely safe. But here’s where it gets interesting. We know that alcohol is very dangerous for driving. In fact, big studies have found that the legal limit of alcohol is approximately equal to cannabis’s effect on driving. So, when you have small or large amounts of THC in your system, it’s about the same as what we legally allow people to drive under the influence of alcohol.
It’s also about the same as driving at night or driving with extra people in your vehicle. It’s a little bit more dangerous to drive at night than to drive during the day. You’re a little bit safer driving alone than when you’re driving with people in your car who could distract you. So, if you’re driving at night and you have people in your car, there’s a higher risk of a traffic accident. If you add cannabis to that, you’re also going to increase that risk.
But the studies on cannabis can be misleading. They find that people who are experienced cannabis users tend to control their driving a little bit better than new users. If somebody is newly using cannabis, they will be much more impaired than people who are very comfortable with what it feels like in their system. Those people have decreased dangers. This doesn’t mean that you’re safe if you use cannabis medicinally all the time. You should be aware that it can still be an impairment to driving.
Another thing that confuses studies is how long THC stays in your system. Let’s say you smoke a joint on Friday night and get pulled over by the police Saturday afternoon. They could take a blood test and find THC in your system, but you may not have any impairment from that THC. Some studies cite this as one of the reasons why we should be leery of cannabis, that it’s more dangerous because it stays in your system for a long time. However, it’s important to remember that cannabis is not toxic to the system. Your system doesn’t really find a need to get rid of it quickly like alcohol, cocaine, and other drugs.
A 2017 American Journal of Public Health study on traffic fatalities found that experienced smokers who drove on a set course showed almost no functional impairment under the influence of marijuana except when it was combined with alcohol. The emphasis here is on experienced users. So, if people are very comfortable with cannabis in their system there does not seem to be any statistically relevant impairment in their driving. Cannabis does increase the effect of other things in our system. It can increase the effect of opioids and reduce opioid usage. That’s a good thing. But it can also increase the effect of alcohol, which does impair driving. When you mix alcohol and cannabis, you are significantly increasing the dangers on the road.
Going a little deeper into the nuances of the study, we find that marijuana users tend to overestimate their impairment when they get high. This means that if people are stoned and about to participate in a driving test they think that they’re worse off than they actually are. They think that they’re more impaired and in danger, and therefore, they slow down. The study found that cannabis use was associated with a decrease in driving speed despite explicit instructions to maintain a particular speed. Users unconsciously decreased their speed because they felt more stoned. This is not an argument for getting stoned and getting behind the wheel, but it does show us that there’s a very different response in our consciousness and in our body when we consume cannabis than when we’re using alcohol. Alcohol findings were almost the exact opposite. People tended to think that they were less impaired than they actually were, and their speed increased under alcohol consumption. When you compare the two they have much different outcomes. Alcohol makes you think you’re safer than you really are.
We now have more than 30 states that have legalized cannabis, and we have found that the highest risk age group for traffic fatalities and alcohol fatalities are 15-25-year-olds. High school and college-aged individuals tend have more traffic accidents. This fascinating study showed medical marijuana laws were associated with an immediate reduction in traffic fatalities in those age groups. What this indicates is that once you relax laws and legalize medical marijuana or decriminalize adult use of marijuana, there is an immediate decline in these accidents. It’s difficult to know exactly what’s causing this, but people are projecting that it’s probably the decrease in alcohol use.
Many of our family members and much of the entire country consumes alcohol, especially around the holidays. Although cannabis is a drug that’s slowly becoming legal, it’s much safer than alcohol in terms of consumption and driving.
The cannabis that impairs you has THC in it. THC (tetrahydrocannabinol) is the psychoactive ingredient in cannabis. It’s important to remember that there’s a secondary, safer molecule in cannabis called CBD. CBD (cannabidiol) is an analgesic. It’s been shown to reduce pain, reduce anxiety, and regulate our system. There are different effects for different strains of plants, but basically, people who consume CBD get some of the medicinal benefits from it without being cognitively impaired. We don’t have as many receptors for CBD in our brain, so we can be clear headed and even drive using CBD.
What do medications for anxiety and pain do in our system, particularly when we’re driving? The data on opioids and driving is pretty sparse actually. So far what they’re finding is that it’s not a major impairment. It’s like using cannabis while driving, driving at night, or driving with multiple people in your car. There’s a slight risk but not a significantly advanced risk like with alcohol.
Valium, Ativan, and Clonazepam are a whole different class of drugs
Now benzodiazepines such as Valium, Ativan, and Clonazepam are a whole different class of drugs that can be very addictive. They don’t necessarily cause euphoria. They don’t necessarily feel good in the system, but it’s very easy for the brain and body to become chemically dependent on them. They’re often used to help people sleep or reduce anxiety. Cannabis is often used to treat similar issues, if done properly.
Experimental studies indicate that Valium can impair driving, and the impairment appears to be significant even after three weeks of continuous usage. This implies that benzodiazepines can still impair users even at smaller doses. This is the opposite from THC. Researchers are finding that people who become accustomed to THC are less impaired in their driving, whereas benzodiazepines are associated with a 60-80% increase in the risk of traffic accidents.
Yes, cannabis can impair your driving. It’s very important to have a designated driver. But it’s nowhere near as dangerous as alcohol as far as how it impairs you and your response to the drug. When you’re on cannabis you feel more in danger than you actually are and tend to reduce your speed. Compared to other drugs designed to reduce anxiety, sleep deprivation, and pain, we can actually seek to utilize cannabis more effectively and decrease impairment from benzodiazepines. They exist for people who need them and can benefit from them, but many people struggle and become addicted to benzodiazepines. The withdrawal syndrome from benzodiazepines is very severe and it impairs your driving more than cannabis. If you live in a state where medical marijuana is legal, it’s important that you know these differences, utilize that information, and consider CBD if you’re leery of the effects of THC.