Approximately one-third of drivers in Washington were drug-positive according to a new study by the National Highway Traffic Safety Administration (NHTSA).

Drugs being tested for included THC as well as antidepressants, narcotic analgesics (pain medication), sedatives and stimulants.

“As we kick-off the Summer Drive Sober or Get Pulled Over campaign, we want drivers to be as aware of the dangers of driving under the influence of drugs as they are of the dangers of driving under the influence of alcohol,” said Darrin Grondel, Washington Traffic Safety Commission Director.

Washington law enforcement officers will join the national Drive Sober or Get Pulled Over campaign aimed at encouraging everyone to get a safe ride, especially if alcohol, prescription or over-the-counter medicine, or other drug use might be causing any impairment.

Extra patrols will run from August 19 to September 5, 2016.

The same study showed that five percent of Washington drivers were alcohol-positive with one percent exceeding the per se limit of .08 BAC. “This shines the light on some good news,” said Grondel, “It is the norm in Washington to drive sober.”

The NHTSA study mirrors the state’s deadly crash data. In 2015, there were 251 impaired drivers involved in deadly crashes. Of these drivers, 20 percent tested positive for alcohol greater than .08 only and another 20 percent tested positive for a single drug. However, nearly 60 percent of these drivers tested positive for multiple drugs, or drugs mixed with alcohol.

“When someone combines impairing substances, such as consuming marijuana and drinking alcohol, they may experience a greater level of impairment than they expected,” said Grondel. “This data shows that combining alcohol and drugs, or one drug with another drug can be a very deadly mix for drivers.