[eldoradude]

From the article:

More to the point, Colorado traffic fatalities between 2007 and 2012 involving operators testing positive for marijuana use increased 100 percent over that period—from 39 in 2007 up to 78 in 2012.

[gogeo]

More to the point, Colorado traffic fatalities between 2007 and 2012 involving operators testing positive for marijuana use increased 100 percent over that period—from 39 in 2007 up to 78 in 2012...

I have no doubt that understates actual DUI occurrence. I would not expect to see the full effect(or have accurate reporting) for another 5-10 years.

[cuban leaf]

From the article:

More to the point, Colorado traffic fatalities between 2007 and 2012 involving operators testing positive for marijuana use increased 100 percent over that period—from 39 in 2007 up to 78 in 2012.

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IOW, the peasant nailed it.

[UnwashedPeasant]

"From the article:
'More to the point, Colorado traffic fatalities between 2007 and 2012 involving operators testing positive for marijuana use increased 100 percent over that period—from 39 in 2007 up to 78 in 2012.'"

As far as I can tell, recreation pot was legalized in Colorado effective September, 2013, so that would have no impact on the stats from 2007 to 2012.

The choice of 2007 and 2012 looks highly selective. Maybe 2007 was abnormally low.

[Uncle Miltie]

Pot was made legal by voters in Co in Nov 2012... but was not available that year. Authors argument on traffic fatalities due to the law fails.