As states liberalise their marijuana laws, public officials and safety advocates worry that more drivers using the drug will lead to a big increase in traffic deaths. Researchers, though, are divided on the question.
Studies of the effects of marijuana effects show that the drug can slow decision-making, decrease peripheral vision and impede multitasking, all of which are critical driving skills. But unlike with alcohol, drivers using marijuana tend to be aware that they are impaired and try to compensate by driving slowly, avoiding risky actions such as passing other cars, and allowing extra room between vehicles.
On the other hand, combining marijuana with alcohol appears to eliminate the pot smoker’s exaggerated caution and seems to increase driving impairment beyond the effects of either substance alone.
“We see the legalisation of marijuana in Colorado and Washington as a wake-up call for all of us in highway safety,” said Jonathan Adkins, executive director of Governors Highway Safety Association, which represents state highway safety offices.
“We don’t know enough about the scope of marijuana-impaired driving to call it a big or small problem. But anytime a driver has their ability impaired, it is a problem.”
– Read the entire article at The Guardian.