A new study found that drivers who often engage to "drugged driving" are three times more at risk to being involved in a fatal car crashes than those who do not drink alcohol or take drugs.

Drugged driving remains as one of the safety issues in the U.S. as well as other countries but no research has been done yet to link drug use to fatal car accidents. This idea convinced the researchers from the Mailman School of Public Health in Columbia University to start the study. They wanted to know if drug use contributed to the growing number of car accidents.

Dr. Guohua Li, lead author of the study and a director of the Center for Injury Epidemiology and Prevention Director, and his colleagues studied the U.S. government data on roadside surveys of alcohol and drug use by drivers and fatal crashes. It was found that almost 32 percent of the casualties on the road and 14 percent of the "control" drivers were found positive with one drug at least.

Findings show that those who were found positive with drugs had thrice the possibility to experience a fatal car crash than those drivers who had no traces of drugs in their system. The most common drugs used by drivers are depressants, stimulant drugs, narcotics, and marijuana in that order.

Comparing the drivers who were free from drugs and alcohol, their risk is twice as much for drivers who were positive for drugs and negative for alcohol, over 13 times positive with alcohol but negative for drugs and 23 times more for those positive with drug and alcohol.

"While alcohol-impaired driving remains the greatest threat to traffic safety, these findings about drugged driving are particularly salient in light of the increases in the availability of prescription stimulants and opioids over the past decade," Li wrote.

The study was published in the online journal Accident Analysis and Prevention.