The article you cite says: > "To put our results into perspective, the levels of driver errors we found are of a similar magnitude to those found in people wit

The article you cite says: > "To put our results into perspective, the levels of driver errors we found are of a similar magnitude to those found in people with a blood alcohol content of 0.08%" This is just comparing against the lower limit of what we legally allow. Clearly, many drunk drivers are far drunker than this. But in any case, I don't think it's "just public pressure to enforce moral values". You can't legally drive on Ambien, but this is a prescribed drug that I don't think people have a moral issue with. While I think the dehydration example above is probably a stretch since it's not really as bad as alcohol, there are other things that are. I'm pretty sure driving with lack of sleep is pretty bad. But it's just not practical to test for it as far as I know.