Authorities in Washington recorded 436 fatal crashes in 2013, and determined that drivers involved in 40 crashes tested positive for THC. 10%.
Driving under the influence should not be condoned but there are other causes with much higher rates.
How many fatal car crashes are caused by people texting? 23 to 28 %.
Texting while driving is 6x more likely to cause an accident than driving drunk.
21% of teen drivers involved in fatal accidents were distracted by their cell phones.
The National Safety Council reports that cell phone use while driving leads to 1.6 million crashes each year