With recreational marijuana set to become legal on Oct. 17, police forces across Canada are stepping up efforts to train officers to detect drivers under the influence of the drug.
The anti-pot group Project SAM claims drug test data show that marijuana legalization in Washington, approved by voters in that state at the end of 2012, already has made the roads more dangerous.
An Arizona appeals court has ruled that marijuana users don't need to be actually impaired to be successfully prosecuted for driving under the influence. The common sense-defying ruling came Tuesday in the case of a man who tested positive for an inactive marijuana metabolite that remains in the body for weeks after the high from smoking marijuana has worn off.
Michigan's medical marijuana law doesn't shield people from charges if they are caught driving after using the drug, the state appeals court ruled Wednesday in another significant decision involving the 2008 voter-approved law.