Fact Checker

Fact Checker: Are drugs now a bigger factor than alcohol in traffic deaths? Checking in on Gov. Reynolds' claim

Iowa Gov. Kim Reynolds gives her Condition of the State address Jan. 15 at the Iowa Capitol in Des Moines. (The Gazette)
Iowa Gov. Kim Reynolds gives her Condition of the State address Jan. 15 at the Iowa Capitol in Des Moines. (The Gazette)

During a June interview, Gov. Kim Reynolds defended her decision to veto a change to Iowa’s medical marijuana laws. The Gazette Fact Checker team has looked further into one of her claims.

The Claim

“Right now, more Americans are killed in drug-impaired traffic crashes than alcohol. It’s switched, from 44 to 38 percent. And a third of Iowa drug-related fatal crashes involve THC.”

Source of claim

Iowa Gov. Reynolds made the statements on a June 3 WHO Radio show, “People’s Press Conference,” hosted by Jeff Angelo. She was talking about why she vetoed legislation that would have allowed higher potency for medical marijuana products sold in Iowa.

Advocates for expanding Iowa’s medical marijuana program pushed to remove the 3 percent cap on THC, or tetrahydrocannabinol, saying the change would allow patients to get the dosage they need without taking excessive amounts, which can be expensive. But Reynolds said it was too much too soon for the program that saw its first sales in December.

She has pointed several times to drug-related traffic fatality data to bolster her point law enforcement officers have legitimate concerns about marijuana use.


When the Fact Checker asked Reynolds where she got the information about national drug-impaired traffic crashes, she referred us to a report from the Governors Highway Safety Administration. The 40-page report uses data from the U.S. National Highway Traffic Safety Administration’s Fatality Analysis Reporting System, an annual census of fatal injuries suffered in vehicle crashes across the country.

The Governors Highway Safety group reports 43.6 percent of drivers in fatal crashes in 2016 with known drug test results were drug positive. This was up from 27.8 percent in 2006, the group reported in its analysis. In a similar 10-year analysis, the Governors Safety group reported 37.9 percent of drivers in fatal crashes in 2016 with known alcohol tests were found positive for alcohol use, down from 41 percent in 2006.

When Reynolds says the drug and alcohol statistics “switched,” she likely means that when comparing drug-related traffic fatalities and alcohol-related traffic fatalities, drug-related crashes made up a larger share in 2016.

But there are some major weaknesses in the data, the Governors Highway Safety report noted. First, not all states test drivers in fatal crashes for the presence of drugs in their bodies. Testing rates by state vary from 2 percent to 96 percent, and states test for drugs differently.

Second, the Fatality Analysis Reporting System data on drug-related fatal crashes includes drivers with any drugs in their systems — even prescription drugs that don’t impair driving.


And when a driver tests positive for multiple drugs, there are inconsistent rules across jurisdictions about which drugs should be included on the forms.

But the biggest caveat in using crash data to measure how marijuana impairs driving is that there isn’t a standard for impairment similar to Iowa’s .08 blood alcohol level for drunken driving. This is according to Tim Brown and Gary Gaffney, lead investigators on drugged driving studies at the University of Iowa National Advanced Driving Simulator.

“There is a significant uptick in drugs being on board, so there is reason to be concerned there are people who have active drugs in their systems while they’re driving.” Brown said. “The extent that contributes to crashes is unknown. More research is needed.”

Data about alcohol-impaired crashes long has been collected and analyzed. These deaths decreased 1.1 percent nationwide between 2016 and 2017, but still there were 10,874 traffic deaths linked to alcohol impairment in 2017 and these deaths accounted for 29 percent of all U.S. traffic fatalities, the U.S. Department of Transportation reported.

The second part of Reynolds’s statement relates to Iowa traffic deaths, tracked by the Iowa Department of Transportation. She says one-third of Iowa drug-related fatal crashes involve THC, the component of marijuana that produces a high.

Iowa had 330 traffic fatalities in 2017, the most recent year for which final data is available.

In those crashes, 77 drivers tested positive for some drugs in their systems, according to Dennis Kleen, the Iowa DOT’s Fatality Analysis Reporting System and driver data manager. Of the 77 with drugs in their systems, 39 had some form of THC, he said.

So the share of drug-related traffic deaths involving THC was 48 percent — which is actually higher than the one-third Reynolds reported. Her lower number likely was from preliminary crash data available earlier in the year, Kleen said.


Alcohol still was linked to more traffic fatalities in Iowa than drugs in 2017. Of the 330 fatal crashes that year, 92 of the drivers, or 28 percent, had a blood alcohol content of at least .01. Drivers with drugs in their systems made up 23 percent of the fatal crashes in 2017.

The same caveats remain about the lack of a standard measure for drug impairment, he said.


Reynolds is right there was an increase in the share of drivers in fatal crashes across the country who tested positive for drugs between 2006 and 2016.

The legalization of marijuana for recreational use (11 states and District of Columbia) and limited medical use (most other states) may have played a role in this. However, the United States also has faced an increase in prescription drug use and an opioid addiction crisis over the past decade.

Reynolds also is right at least one-third of Iowa’s drug-related traffic fatalities in 2017 involved drivers with THC in their systems.

The context missing in her statements is that there’s not yet a standard way to test drivers for drug impairment, so experts in the state and federal transportation agencies have warned against drawing comparisons between drug and alcohol impairment. And, in Iowa, alcohol-related traffic deaths still outnumber drug-related traffic deaths.

We give Reynolds a B because while she had the numbers right about increased drug use among drivers involved in fatal crashes, conclusions about drug-impaired driving still need more research.


The Fact Checker team checks statements made by an Iowa political candidate/officeholder or a national candidate/officeholder about Iowa, or in ads that appear in our market. Claims must be independently verifiable.

We give statements grades from A to F based on accuracy and context.

If you spot a claim you think needs checking, email us at factchecker@thegazette.com.

l This Fact Checker was researched and written by Erin Jordan of The Gazette.

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