SPOKANE, Wash. -

While people driving high have always been a concern, it's even more so now that legal weed is so accessible. The Washington Transportation Safety Commission is going to extra lengths to inform people that driving high is a crime.

“Our deputies are actually seeing an increase in drivers under the influence of marijuana,” Spokane Valley Police Chief Rick VanLeuven said.

He said that it's been a busy year for his officers in the Spokane Valley. Only eight months in and already there's been 37 DUI arrests for marijuana impairment. That number is getting ready to exceed the 44 arrests seen in 2013 and is triumphing over the 17 in 2012.

“People that think that smoking marijuana is legal, they need to understand that they cannot do that and drive,” VanLeuven said.

To bring marijuana related DUI's down, officers statewide are being trained to recognize drivers under the influence and get them off the road. Drug Recognition Experts go through a two week classroom and skill training program that covers seven drug categories and the signs and symptoms.

"We're not looking for you to fail, we're looking to make sure you're not impaired, simple as that," Master Police Officer Mike Thomas with Liberty Lake Police Department said.

He's one of the roughly 20 DRE officers in Eastern Washington. DRE officers respond to arrests and accidents that are believed to be marijuana related.

“I always ask, 'Have you had any alcohol to drink today?' 'Have you been smoking marijuana?' 'Have you been taking any medications or drugs?'” Thomas said. “Depending on your answers and how you're answering is where I go from there."

Officers can perform a field sobriety test to check for any kind of impairment. They can also request a blood or urine test, but need a signed search by the judge to do that. If a driver is arrested for a DUI, the minimum penalty is a day in jail, a year probation and ignition interlock.

"We are going to proactively enforce this as best we can to keep our streets as safe as possible," VanLeuven said.

The legal limit for marijuana is 5 ng/ml in the blood.