According to figures from the Georgia-based Centers for Disease Control, doctors in the United States write more than 200 million opioid prescriptions every year, which equates to more than 66 prescriptions for every 100 Americans. This worries lawmakers and police departments because drugs like fentanyl and oxycodone affect drivers in similar ways to alcohol.

Much of the research into opioid use has focused on the societal costs of the widely available and highly addictive medications, but two researchers from Columbia University recently took a different approach. They wanted to find out if the opioid epidemic that is sweeping the country is having a detrimental effect on road safety, and they found that the number of drivers who die each year while under the influence of the drugs has risen from about 1% in the 1990s to an alarming 7%.

The study, which was published in the scientific and medical journal JAMA Network Open, was based on National Highway Traffic Safety Administration reports about 18,321 fatal two-car accidents that occurred between 1993 and 2016. When the Columbia University researchers looked at the results of toxicology tests conducted on the deceased drivers involved, they discovered that the presence of opioids in the bloodstream doubled the chances of being killed while behind the wheel. More than half of the opioid-impaired drivers who died were killed when their vehicles strayed into another traffic lane.

The results of the study suggest that many of the victims of opioid-impaired drivers are killed or catastrophically injured in head-on collisions. Establishing liability in lawsuits filed on behalf of car accident victims or dependent family members is often relatively straightforward in these cases, but reckless drivers are unable to make restitution if they are dead or incarcerated. In situations like this, experienced personal injury attorneys may be able to initiate civil litigation against the negligent motorist’s estate or insurance provider.