We do in the US, but the general public (and jurors) can be skeptical of breathalyzers, no matter how accurate they are. So the police are forced to come up wit

We do in the US, but the general public (and jurors) can be skeptical of breathalyzers, no matter how accurate they are. So the police are forced to come up with ancillary evidence in case someone contests that they were drunk. As a law clerk I watched a jury find a guy not guilty of a DUII who blew a .18 on a properly calibrated breathalyzer because of a bunch of wonky arguments by his defense attorney about how the officer did not conduct other field sobriety tests. - At a .18 BAC you are drunk and on the brink of blacking out, unless you are a full-fledged alcoholic.