In Texas marijuana is illegal under state and federal law. In other states the law allows marijuana though federal law prohibits it. Last December a driver who used alcohol and Tetrahydrocannabinol (THC) was impaired & pulled over at 0200 (2 am). According to reports his "blood-alcohol content was at .155, just short of twice the legal limit. It also showed trace amounts of tetrahydrocannabinol, the intoxicating component in marijuana." 

It is something to think about, as one reason to advocate marijuana decriminalization or legalization is the THC to reduce pain. Yet, it is also the THC which impairs one. So to anyone who smokes weed, don't smoke and drive, nor drink and drive. Tragically this combination led to a pharmacy student's death after being pulled over and shot by a policeman.

This is more tragic because a pharmacy student studies drugs and its effects on the body. though illegal substances aren't normally the scope of pharmacy school, legal ones are, including ethanol or alcohol. Judging by the amount of drinking that some of my peers did, knowledge doesn't always led to correct decisions of moderation of imbibing.

Source:http://www.dcclothesline.com/2014/03/23/autopsy-determines-texas-cop-fatally-shot-student-back/
'Autopsy determines Texas cop fatally shot student in back'