Marijuana (or cannabis) has been in the spotlight recently as more and more states throughout the US pass legislation legalizing its use for medicinal and/or recreational purposes.

There are currently 24 states in the US (including Pennsylvania) which have passed legislation legalizing the use of medicinal marijuana and 4 of those states have legalized marijuana for recreational purposes too. 

One of the main issues being raised now is whether or not marijuana affects a driver’s performance, and if so, how driving under the influence of marijuana should be enforced.

This article discusses findings from a recent study that looked at marijuana DUI arrests in order to determine the reliability of the methods used to determine driver impairment.

Does Marijuana Affect Driver Performance?

Both advocates and opponents of legalized marijuana agree that the cognitive and psycho-motor effects of cannabis use can result in deteriorated driving performance, but the exact relationship is not exactly clear.

Many organizations have commissioned studies aimed at helping advance our knowledge of marijuana and its effect on an one’s ability to safely operate a vehicle.

New Study Shows Officers Are Using Unreliable Methods To Identify Impairment From Marijuana In Drivers

Driving Under The Influence Of MarijuanaAccording to a recent study conducted by AAA, the nation’s largest auto club, many Pennsylvania drivers are being wrongly convicted of driving under the influence of marijuana due to the unreliable methods used to determine impairment.

The study, entitled “An Evaluation of Data from Drivers Arrested for Driving Under the Influence in Relation to Per se Limits for Cannabis,” claims that the methods currently used to determine impairment from marijuana in the US are not scientifically based and are unreliable.

Researchers looked at data on more than 5,000 drivers arrested for driving under the influence of marijuana who had tested positive for cannabis, as well as data from a control group of hundreds of drug-free subjects.

After reviewing the data, researchers found that there was no correlative relationship between increased THC levels and performance on standard field sobriety tests.

The Problems The With Current Methods Used For Determining Marijuana Impairment

The problem is that legislators are looking to the standard methods used to determine alcohol intoxication in drivers suspected of operating under the influence and are attempting to apply similar methods to determine marijuana impairment.

When an individual is suspected of driving under the influence of alcohol, law enforcement officers administer a chemical test (usually breath or blood) to determine the individual’s blood alcohol concentration (BAC).

Similarly, when an individual is suspected of driving under the influence of marijuana, law enforcement officers administer a chemical test (usually blood) to determine the driver’s THC level, the primary active chemical in marijuana.

Years of research has found that blood alcohol concentration is a relatively accurate measure of impairment.

However, not much research exists to support that blood THC concentration is an accurate indication of impairment from marijuana.

Drivers & DUI Defense Attorneys Call For A Change

At the moment, if a driver is found to be operating a motor vehicle with a THC level above the legal limit, that driver can be charged with Driving Under The Influence of Drugs (DUID).  But the legal limits for cannabis vary widely by state and some states do not even have a legal limit in place!

For example, the legal limit in Pennsylvania is 1 nanogram per milliliter of THC, while the legal limit in Colorado, Washington and Montana is 5 nanograms per milliliter of THC.

Drivers and DUI defense attorneys across the country are now calling on legislators to reconsider the current methods used to enforce driving under the influence of marijuana.

For more interesting articles about DUI laws in Pennsylvania and throughout the US, visit our DUI blog here.