The answer is not straightforward and depends on various factors. Generally, if you have consumed any amount of alcohol, it is advisable to decline a breath test. This is because any level of alcohol in your breath can indicate probable cause for an arrest and can be used as evidence in court. Moreover, people tend to underestimate the number of drinks they have consumed after they start drinking, and it can take just a couple of strong drinks to exceed the legal limit of .08.
In Austin, if you refuse a breath test, you will be required to undergo a blood BAC test, usually with the availability of a Magistrate Judge 24/7 in the Travis County jail. However, it’s important to note that your BAC level fluctuates and decreases over time. If it drops below .08 before the test, it weakens the State’s case against you, which can work in your favor. Also, the State needs to prove that you were intoxicated while driving, not just during the test. The farther away those two events are, the more difficulty the State will have in proving its case.