AURORA, Ill. (WAND) - AAA is issuing a warning, reminding people driving high on marijuana is dangerous and illegal.

According to a survey conducted last month by AAA, two-thirds of AAA members in Illinois said that they are "extremely" or "very concerned" about the impact of marijuana use on roadway safety. 

An analysis by the AAA Foundation for Traffic Safety found the proportion of drivers involved in fatal crashes who had recently used marijuana doubled in Washington state after it became one of the first to legalize recreational use.

"Impaired driving jeopardizes public safety on our roadways regardless of whether the substance used is legal, prescribed, obtained over-the counter or purchased in a retail setting," said Molly Hart, spokesperson for AAA-The Auto Club Group. "Even after recreational marijuana becomes legal in Illinois, driving under the influence of the drug will remain a serious offense."

Anyone who uses marijuana should understand how it can negatively impact their ability to drive safely.

Marijuana can decrease car handling, performance and attention, while increasing reaction times, following distance and lane deviation.

Impairment from marijuana is greatest within the first hour after use.

While the state has established a per se limit of 5 ng/mL of THC in the blood (the point at which a driver is automatically considered intoxicated under the law), it is possible for marijuana users to be dangerously impaired and charged with a DUI at lower concentrations.

Mixing alcohol and marijuana may increase the level of impairment.

"Marijuana affects people differently based on a wide range of factors," continued Hart. "If you plan to drive, don't consume marijuana.  And if you consume marijuana, don't drive."