Too High to Drive? New App Allows Marijuana Users to Test Their Impairment Level

Getting beyond "I think I'm OK."

Minnesota sisters invent device to test for high drivers

Driving while stoned leads to more traffic accidents in a country

Is Driving High as Dangerous as Driving Drunk? - The New York Times

Too high to drive? Enforcement of drug-impaired driving in Ontario could face roadblocks similar to those encountered in Colorado

and meticulous,” Dunphy said.

Motorists smelling weed more on N.J. highways

Legal marijuana: Data show minimal effects on teen use, traffic deaths

Driving After Taking Any Form of Marijuana Is Unsafe

Testing drivers for cannabis is hard. Here's why