How Should Massachusetts Deal With Marijuana-Impaired Driving?

Last month, the state rolled out its PSA campaign against driving while high. As the Cannabis Control Commission moves closer to granting the first retail license, state officials are working on policy recommendations to help prevent people from driving under the influence of marijuana and holding those that do accountable.

We'll look at the ways marijuana impairment differs from alcohol, and why it is so much harder for law enforcement to identify a stoned driver than a drunk one.

John Carmichael, Walpole police chief, member of the Special Commission on Operating Under the Influence and Impaired Driving. He tweets @walpolechief.

Dr. Kevin Hill, director of the Division of Addiction Psychiatry at Beth Israel Deaconess Medical Center. He tweets @drkevinhill.