A new study finds the number of drivers fatally injured in automobile accidents who tested positive for one or more substances is rising, according to U.S. News & World Report. The study, by the Governors Highway Safety Association, found that 44%of fatally injured drivers with known test results tested positive for drugs in 2016, up from 28% a decade earlier. More than half of the drivers had marijuana, opioids or a combination of the two in their system, the study found. Thirty-eight percent tested positive for marijuana, 16 percent tested positive for opioids and 4 percent tested positive for both. Among the drivers tested for alcohol, 37.9% tested positive in 2016, down from 41% in 2006.