[Dueller]

Interesting question, stuart, and much more complex than you might think at first blush.

In essence the answer to your question is a qualified "yes." All states have "implied consent" laws on the books. The jist is by operating a motor vehicle on the public highways you impliedly consent to taking a breath test for alcohol. Of course you can refuse, but if you do your license may be administratively suspended for a period. Note that I said administratively. This is different from losing your license due to a criminal conviction for DUI. As a practical matter officers usually want to have some probable cause to suspect you of DUI before they will push for the breath test. Going back to basic civics classes you know that you cannot be deprived of a fundamental right or property without due process of the law (where the 4th amendment comes in), however the courts have ruled that a driver's license is not a right or "property" but rather a privilege granted by the states.

And random roadblocks have been upheld as constitutional as the public interest to keep drunk drivers off the road is of greater importance than the personal inconvenience of a brief investigatory stop.

Answer your question?