According the to the National Highway Traffic Safety Administration (NHTSA), marijuana users are about 25 percent more likely to be involved in a car crash than drivers with no evidence of THC in their system. With the loosening of marijuana laws and the increase of marijuana consumption for medicinal purposes in Indiana and nationwide, impaired drivers are becoming in increased risk on roadways. In fact, recently published data from AAA suggests a correlation between marijuana usage and an increase in car accident fatalities.

Driving under the influence of marijuana is a serious offense in Indiana. Although medical marijuana is legal in the Hoosier State, there are stringent laws related to marijuana use while driving. Under Indiana law, a driver can be arrested and charged with operating a vehicle while intoxicated (OWI) even if they have a trace amount of THC in their system.

Prior to July, 2021, Indiana had a zero-tolerance policy for THC in the bloodstream while driving. Any driver found to have a trace amount of THC in their system could be charged with OWI. There is now an exception for individuals who have a valid prescription for medical marijuana. These drivers can have up to five nanograms of THC per milliliter of blood in their system and still operate a vehicle legally.

However, it is important to note that this exception only applies to individuals with a valid prescription and if a driver does not have a prescription, even the slightest amount of THC in the system can lead to an OWI charge.

The risks associated with marijuana and operating a motor vehicle cannot be overstated. Marijuana impacts a person’s ability to focus and react to roadway conditions. Drivers under the influence pose a significant danger to themselves and others. It is also important to understand that marijuana can remain in your system for an extended period — long after the immediate effects have worn off. THC can be detected in a person’s bloodstream for up to 30 days after last use.


If you are the victim of an accident with injuries due to a driver under the influence of marijuana, any related negligence may have an impact on your case and potential award amount. However, each personal injury case is unique and numerous factors will determine how, if at all, your case will be affected. Circumstances such as the extent of injuries involved and how much THC was in the driver’s system are just a few potential factors to consider.

If you have been involved in a car crash and the other at-fault driver was under the influence of marijuana or any other substance, you’ll need to contact an experienced Indiana personal injury lawyer immediately. We will assess your case at no cost and if you retain our firm, we will work on a contingency basis, meaning there is no cost unless there is a settlement or jury verdict award on your behalf.

Call 317-636-0808 or email us for a FREE and confidential consultation.