How should the law treat stoned drivers?

Now that it’s legal in two states to use marijuana for the purpose of getting high, authorities are considering how to regulate driving while stoned. It’s a complicated question, because testing is difficult and researchers differ over the level of impairment marijuana causes.

There’s some evidence that young people consider it less likely they will suffer negative consequences if they drive stoned than if they drive drunk.

Twenty states, including Minnesota, have legalized the use of marijuana for medical purposes.

Today’s question: How should the law treat stoned drivers?