[jajko]

The test is trivial - take a breathalyzer and compare results after say 2, 3, 5 beers before and after. Some mental / IQ test could be added to make sure we don't have folks driving around passing breath test while being very drunk.

Something tells me if they can't provide such a trivial result, it ain't working as folks expect (and god knows what nasty side effects it can have).

[Etherlord87]

a hangover isn't strictly correlated to alcohol - you can have a hangover with a 0% alcohol reported by the breathalyzer. I've read drinking alcohol starts processes that damage the brain for the following 3 weeks, and the brain needs additional 3 weeks to heal. Obviously what people mean by a hangover has a much shorter span, I think mostly related to dehydration.