In theory, sure. But many other things can affect a driver in ways that make them dangerous. Being tired has been demonstrated to affect people similarly to h

In theory, sure. But many other things can affect a driver in ways that make them dangerous. Being tired has been demonstrated to affect people similarly to how alcohol affects people, but almost every single person driving to work is driving tired. That doesn't suggest we should allow people to drink and drive, but it does illustrate that an absolute hard line policy against having any alcohol in one's blood is a bit ridiculous given the other ways someone may be dangerous. Same goes for a lot of medicines people take. Some medicines will specifically tell you not to drive, and other medicines may react with other medicines to make a driver dangerous (and the driver may not even know it). I have a better solution: reduce the need for people to drive themselves around as much as possible (public transport).