There is a big difference between passing a law that requires people to wear a seatbelt and integrating an electronic device that prevents your car from operati

There is a big difference between passing a law that requires people to wear a seatbelt and integrating an electronic device that prevents your car from operating normally when it 'detects' the presence of alcohol. Edit: In addition, detecting the level of alcohol is a much more difficult and non-straightforward problem then checking if a seatbelt is plugged in. With a seatbelt you can have a simple circuit that gets completed when you plug the metal into the socket. But how will a breathalyzer work? Can it tell that I the driver am sober when my passenger(s) are heavily intoxicated? If there isn't a tube I have to blow into, I assume it passively scans the cabin air? I vaguely remember a push to install a part into cars that prevented you from driving if the seatbelt was not fastened. It caused a lot of problems and now we just have a warning light and a pestering beep instead.