Would you include getting behind the wheel if you are tired, sick, stressed, taking antihistamines, or impaired in any other non-illegal-drug related way as well? Because I'm pretty sure those can impair drivers to the same degree. It's just that driving while impaired due to drugs is seen as being a moral failure, while it's perfectly socially acceptable to drive in other circumstances.

What are the numbers of deaths related to these? You quoted 39% of auto deaths as being alcohol related elsewhere. If we determine there was a problem, we should seek to address it. At the moment, it sounds like you're just trying to sidetrack the conversation.

We can measure blood alcohol so we can estimate the degree of impairedness. Furthermore, it is already illegal.

Because changing human behavior is such an easy task, especially changing the behavior of people who are already intoxicated...

No one said it would be easy. Isn't saving 10,000 lives a year worth some effort?

And waiting until the problem occurs is obviously not the time to try and change the behavior.