Impaired Driving:  Alcohol depresses inhibitions and provokes risk-taking behaviour.  Thousands are killed and injured each year by drivers under the influence of alcohol.  Whereas, cannabis tends to make the individual more focussed, careful and they want to drive slower, not faster. 
Hundreds of thousands of people are killed by alcohol and tobacco every year.  
There are no documented deaths caused directly or indirectly by marijuana.
But the fear campaign goes on... Why?  Because medical natural marijuana cannot be patented by the Big Drug companies and it will cut into their enormous profits from opioids which kill millions every year.