As incidents of drunk driving decrease, another cause of road accidents is on the rise: drugged driving. The advocacy group Governors Highway Safety Association (GHSA) released a new report stating that more and more Americans are driving while drugged, Health Day reports.

In a nationwide survey conducted in 2013, 62.6 percent of fatally injured drivers were tested for drugs. Of these, 30.3 percent tested positive for drugs. Furthermore, a voluntary roadside survey conducted by the National Highway Traffic Safety Association (NHTSA) from 2013 to 2014 found that 22 percent of all drivers tested on weekdays and on weekend nights were positive for drugs, the GHSA report said.

Apparently, drugged driving is more complicated than drunk driving because there are hundreds of drugs - whether legal or illegal - that can impair a driver, and the effect of these drugs can vary from one person to another.

Second, jurisdictions on drug use are not the same for all states, making it difficult to prosecute or convict a person from drugged driving compared to drunk driving. Medical marijuana, for example, is legal in 23 states. Marijuana for recreational use is legal in Oregon, Alaska, Washington and Colorado. Just recently, Oregon legalized the sale of recreational marijuana.

In the 2013 nationwide survey, 34.7 percent of those who tested positive for drugs had marijuana in their system, while 9.7 percent had amphetamines.

"Every state must take steps to reduce drug-impaired driving, regardless of the legal status of marijuana," GHSA executive director Jonathan Adkins said in a press release. "We encourage NHTSA to issue guidance on best practices to prevent marijuana-impaired driving."

The GHSA report recommended that states evaluate the effects of drugged driving and to update their respective laws on the issue. The report also said all fatally injured drivers should be tested for drugs.

Report author James Hedlund noted that much is yet to be known about drug-impaired driving, which is why he recommended in the report that all crash data related to drugged driving be tracked in order to have a better assessment of the problem.

"While this report summarizes the research and data available, it also highlights how much remains unknown," Hedlund said in the press release. "The recommendations in the report will help states refine and augment their efforts to detect and deter drug-impaired drivers."