What is an 'objective test' for intoxication?

What is an 'objective test' for intoxication?

Neil Shouse (Defense Attorney) gives expert video advice on: What is the legal definition of 'drunk driving'?; What is a 'DUI'?; What is a 'DWI'? and more...

Primarily, an objective test would be a blood test, a breath test or a urine test that determines your BAC level and assigns a numeric value to your level of intoxication. This doesn't depend on the impressions of the police officer. It is something that is objectively determined and is presumably the same for everybody.