Do you know what hours for example doctors on duty work? The system that is trying to save money on the back of junior doctors is kind of forcing them to work these excessive hours, so no, it cannot easily avoided.
It is really all about money. A breathalizer in every car is pretty useless as long as you do not prevent another person to "unlock" the car. Imagine a father having a few beer during a bbq in the garden with friends. Come early evening, the son has to go for football practice and so the father would order him to unlock the car for him, so he can drive the son to his training.
You cannot solve a problem that is founded in the society (general availability and acceptance of alcohol) with technical means, I am afraid.