A new study shows motorists are being convicted of driving under the influence of marijuana based on arbitrary state standards that have no connection to whether the driver was actually impaired, according to a recent newspaper article.

The information was released by the AAA Foundation for Traffic Safety, the nation's largest auto club, which commissioned a handful of studies to see what effects, if any, were shown in statistical data. Washington is one of six states that have set specific limits for THC in drivers' blood. THC is the chemical in marijuana that makes people high. The other states are Colorado, Montana, Nevada, Ohio and Pennsylvania.

Two main findings stand out in the AAA studies:

• Fatal crashes involving drivers who recently used marijuana doubled in Washington after the state legalized the drug.
• Legal limits, also known as per se limits, for marijuana and driving are arbitrary and unsupported by science.

One study quantified the prevalence of marijuana involvement in fatal crashes in Washington from 2010 to 2014. Also included in the study is an investigation into whether the prevalence changed after legalization of recreational use of marijuana and creation of a new per se limit for driving under the influence of marijuana which took effect in December 2012.

The study concluded that about 10 percent of all drivers involved in fatal crashes in Washington during the 2010-2014 timeframe had detectable THC in their blood. In addition, there was evidence that the proportion of drivers in fatal crashes who were positive for THC increased after Initiative 502 legalized recreational marijuana use for adults age 21 and older. However, the increase did not start until about nine months after the initiative went into effect. By 2014, the number and proportion of drivers in fatal crashes who were positive for THC were more than double the averages from the prior four years.

Another study analyzed Washington State Patrol data in order to document:

• The trends in THC involvement over time and in relation to the legalization of cannabis.
• The prevalence of THC alone and in combination with other potentially intoxicating drugs.
• The estimated time to blood draw under real world conditions.
• The relationship between estimated time to blood draw and the level of THC detected.

Data from the study indicated increases in the proportion of DUI cases involving THC and an increase in the median level of THC in cases from 2005-2014, however there was no significant additional increase related to the passage of Initiative 502 in 2012.

According to the Seattle Times article, driving under the influence of marijuana doubles the risk of a crash, yet using a hands-free cell phone while driving, which is legal in all states, quadruples the risk of a crash.

Because convictions for driving under the influence of marijuana are potentially based on arbitrary standards, drivers who find themselves charged under RWC 46.61.502 have a right to the best defense. If you have been arrested, suspected of DWI, call the Seattle law office of Aaron Wolff at (206) 504-2500.