Blood Test For Marijuana Unreliable For DUI Penalty
Once again, a bill that seeks to punish prior use of a controlled substance with an automatic DUI conviction is before the Kentucky legislature.
Like its predecessors, Senate Bill5 cleverly attempts to bootstrap an ill-advised rule regarding all drugs onto a rule created for the purpose of measuring alcohol impairment. Under SB5, a driver who tests positive for traces of marijuana can be convicted of "driving under the influence" even if that driver is unimpaired at the time of arrest.
While such laws do little to actually make roadways safer, they do send many innocent people to jail and saddle them with criminal records for the rest of their lives. Current Kentucky DUI law requires prosecutors to prove that a suspect was impaired while driving. SB5 seeks to circumvent current evidentiary standards by removing this requirement. If lawmakers want to clog court dockets, cost taxpayers more money and make it tougher for Kentuckians to find and retain employment, then this is the bill to support.
SB5 attempts to create the appearance of scientific reliability by requiring blood tests to be administered within two hours of operating a vehicle. However, the two-hour standard was developed decades ago for measuring impairment caused by alcohol, not drugs like marijuana.
Moreover, the test referred to in SB5 is not a test for marijuana impairment, but merely a test for marijuana's presence, which is not what DUI laws are supposed to punish.
The effect and perhaps even the aim of legislation like SB5 is to punish prior drug use — predominantly marijuana use — by convicting drivers of DUI without scientifically reliable evidence that they were operating a vehicle while under the influence of anything.
"Zero-tolerance" laws are more than unjust; they are scientifically unsound, which is exactly why not one single state applies such a rule to alcohol. Furthermore, these laws are even less suited for marijuana, the traces of which are detectable by drug tests long after its intoxicating effects have worn off.
Marijuana impairment peaks within minutes of use and is seldom severe or long lasting, according to the U.S. Department of Transportation. Conversely, alcohol impairment peaks much later and lasts for hours, meaning there's a true correlation between high alcohol levels and driver impairment.
A driver with high levels of THC (the active psychotropic ingredient in marijuana) in the blood may not be impaired in any manner if time has passed since the substance was last used. The inability to accurately measure marijuana impairment is why both the National Highway Traffic Safety Administration and the National Institute on Drug Abuse have stated that marijuana impairment testing via blood sampling is unreliable.
Driving under the influence of any substance is dangerous and should not be tolerated, but sending innocent people to jail for DUI using methods incapable of accurately measuring impairment is not the answer.
Lawmakers should reject SB5 as they have done in the past, instead focusing on finding real, scientifically valid ways to detect impaired drivers and get them off Kentucky highways.