First, here is the key quote from a story in today’s Chicago Tribune:
There are fewer drunk drivers on the road, but their place has been taken by people high on marijuana and prescription drugs, according to two reports from the National Highway Traffic Safety Administration.
The number of inebriated drivers has declined by almost a third since 2007, but in a 2014 survey nearly 1 in 4 on the road tested positive for a drug that endangered them or others, NHTSA said.
“The latest roadside survey raises significant questions about drug use and highway safety,” NHTSA Administrator Mark Rosekind said. “The rising prevalence of marijuana and other drugs is a challenge to everyone who is dedicated to saving lives and reducing crashes.”
The survey is a voluntary, anonymous effort to collect information from regions across the country. Road signs tell drivers that a data-collection site is ahead of them, and those who wish to participate pull over. The survey has been taken five times in the past 40 years.
The 2014 survey found that about 8 percent of people on the road on weekend nights had alcohol in their system, and slightly more than 1 percent were above the legal limit. That was 30 percent below the 2007 figure, NHTSA said, and an 80 percent drop since the first survey was taken in 1973.
But the number of people with drugs in their system was found to be on the rise. It jumped from 16.3 percent in 2007 to 20 percent of weekend nighttime drivers in 2014. Drivers with marijuana in their system soared by almost 50 percent.
So why do I say that this study is flawed? Because it equates the mere presence of drugs in one’s system with impairment, which is untrue. A person could smoke marijuana and test positive for it a month later. So all this study is showing is that more people are driving around with the residue of drugs in their system, not that they are necessarily driving while impaired from narcotics.