Driving while under the influence of marijuana is rising in states that legalize marijuana. More and more states are legalizing marijuana (either recreationally or medicinally) and those states are experiencing increasing rates of high driving. High driving is a problem because of law enforcement, unlike with alcohol, possesses no reliable tools or tests to assess impaired drivers. Moreover, marijuana can affect the body and mind in different ways, depending on the type of marijuana consumed and the method – putting even greater strain on law enforcement, dispensaries, and drivers to identify when they are compromised and when drivers are safe to operate a vehicle
High driving is Drunk Driving
Driving while impaired is traditionally associated with alcohol. The law does not discriminate between the various substances. Driving while under the influence of marijuana, prescription medication, hallucinogens, or other illicit substances is illegal if it impairs the driver’s ability to operate a vehicle. The law focuses on drunk driving by using the bright-line 0.08 percent blood-alcohol content measurement. The issue concerning enforcement and assessment of “high” drivers is that the scientific community hasn’t reached a consensus on when a person is “high” and when that “high” wears off.
For example, while alcohol affects everyone in different ways (depending on weight, sleep, diet, and other factors), the scientific community and government regulators agreed that 0.08 percent BAC is the bright-line threshold for impaired driving. Marijuana remains a Schedule I drug per federal regulations which severely constrains researchers’ ability to study it which has to lead to the current lack of scientific understanding.
How Marijuana Affects the Body and the Ability to Drive
According to a study by the National Institute on Drug Abuse (the only major federal study to publish its finding so far), found that drivers under the influence of marijuana increase the amount of weaving they perform within a lane. The study looked at 250 parameters of driving but published its finding assessing only three:
- Changing lanes;
- Speeding; and
- Weaving within the lane.
The study compared the results to alcohol and found that drunken drivers typically increase their speed and the rate at which they change lanes. However, marijuana drivers only increase the weaving within the lane, there was no measurable change on speeding or lane changing for high drivers.
The goal of the study was to assess how long it takes THC (the psychoactive ingredient in marijuana) levels to drop in a person’s blood. The study assessed 18 cannabis smokers and measured their reactions in a driving simulation. The study found that 13.1 ug/L of THC in the blood roughly equaled the same amount of weaving a driver under the influence of alcohol at 0.08 percent BAC might perform. The researchers emphasized that the study focuses on THC levels while operating a vehicle, the police cannot use these same results because most high drivers can only be tested at hospitals, hours after they would be arrested.
The Legalization Movement
To date, eight states and Washington D.C. have legalized recreational marijuana. They are joined by 22 additional states that have legalized medicinal marijuana. Those states range from Montana and Louisiana to New York and Florida. Some additional states, like Alabama and Mississippi, permit medical marijuana in extreme medical circumstances, such as epilepsy.
Colorado and Washington were the first two states to legalize recreational marijuana in 2012, and they opened their first retail operations in 2014 and 2015. They are joined with Nevada and Oregon and California will set-up a framework for legal marijuana in 2018.
High Driving Increases in States that Legalize Marijuana
According to a study conducted by the Highway Loss Data Institute, found that collision claims rose 2.7 percent in Colorado, Washington, and Oregon. The study compared these three states to their pre-legalization rates, and surrounding states wherein cannabis remains illegal.
Between January 2012 and October 2016, the study found that accident claims rose 4.5 percent in Oregon, 6.2 percent in Washington, and 16 percent in Colorado. The study cautions that it is not ascribing causality to the increase in crash rates and the legalization of cannabis. However, the study’s authors emphasize that there is a strong correlative effect. The researchers caution that a combination of road construction increased distracted driving rates, and increased number of miles driven (because the economy is more robust which usually results in more mile driven).
The researchers also clarify that they cannot establish a link because, as stated above, there is no established method to assess drivers under the influence of marijuana. Until science and the government can agree on study methods for marijuana, it is likely that law enforcement will have to make do with traditional field sobriety tests, dispensaries will issue general warnings, and drivers should err on the side of caution.