It should be stated first and foremost that without a doubt alcohol yields greater impairment on driving and operating a motor vehicle in comparison to marijuana. However, like alcohol, marijuana affects one’s ability to drive based on the amount or dose. According to most researchers on the topic, the greater the amount of marijuana one ingests or smokes, the more likely that individual is to get into an accident – especially with low tolerance.
Of the two substances, alcohol is clearly more of a danger to consume before driving. The affect that alcohol has on one’s complex motor skills is extremely powerful. It should be made clear is that these two substances generally affect individuals differently – in other words, there is disparity among users. There is generally greater disparity between two individuals that have ingested marijuana compared to people that drank alcohol. Studies have shown that absorption of THC differs and in part due to different ways of smoking marijuana and levels of tolerance.
Alcohol vs. Marijuana: Driving Under the Influence
Marijuana: High doses have been found to impair automatic driving functions and less likely to impair complex driving tasks. Although some automatic driving tasks are impaired, studies show that marijuana users generally make up for the impairment by using various behavior strategies. Read more about how marijuana affects driving performance.
Alcohol: More likely do impair complex driving tasks. In comparison, alcohol will impairs the ability to drive significantly more than marijuana.
Alcohol + Marijuana: The combination of these two substances produce the most profound impairment compared to either one alone.
Alcohol vs. Marijuana: Driving Impairment Comparison
Alcohol and Driving
- Alcohol impairs driving differently than marijuana
- Alcohol impairs driving more significantly than marijuana
- Alcohol significantly increases crash risk
- Drunk drivers are responsible for 25% motor vehicle fatalities
Marijuana and Driving
- Marijuana impairs driving in a dose dependent manner
- It is inconclusive as to whether marijuana is directly linked to increased crash risk
- Alcohol in combination with marijuana produces greater impairment than either alone
Source: http://www.ncbi.nlm.nih.gov/pubmed/19340636
THC vs. Alcohol Equivalency
Below is the THC alcohol equivalency to be considered driving under the influence. I’m not sure if people will be able to determine this based on the weed that they’ve smoked. But for scientific purposes, the amounts are listed below.
- 300 microg/kg THC = blood alcohol concentration (BAC) >/=0.05 g/dl
- 7-10 ng/ml THC = BAC 0.05%
- 3.95% THC = 0.05 BAC in regards to equilibrium and brake latency
Source: http://www.ncbi.nlm.nih.gov/pubmed/17916224
Source: http://www.ncbi.nlm.nih.gov/pubmed/9862085
Do you smoke marijuana while driving?
The fact is that people are going to do what they want and feel comfortable with while driving. Chances are preaching to them to stop driving high isn’t going to really do much to help the cause. In my time I have been in the car with individuals that are high and individuals that were drunk. In my opinion, it’s not a smart option to be in the vehicle with either.
This is more of a personal issue with a lot of different variables. If you are going to drive high, you may want to consider some factors such as: What is your tolerance? How much weed did you smoke? Do you feel safe? Are you a good driver when you’re not high?
Source: http://www.ncbi.nlm.nih.gov/pubmed/19340636
Sober Driving Ability: Some People are Bad Drivers
There is also the factor of driving ability sober.
I personally believe that certain people just are terrible drivers even sober.
Throw in miscellaneous factors like sending / reading text messages, doing your make up, eating food, talking on a cell phone, putting on eyeliner and makeup, and your accident risk goes way up as well. There are many different factors to take into account here.
Obviously if you want to be safest and minimize your risk, drive sober. If you choose to drive high, drunk, or crunk (a combination of the two), you are putting your own life at risk as well as those of other drivers.
Additional reading: http://www.ncbi.nlm.nih.gov/pubmed/17332811