All states have set a legal blood alcohol content, above which you can be charged with driving while intoxicated or driving under the influence. Additionally, most states have “implied consent” laws under which law enforcement officials can arrest you for driving drunk even if you refuse to submit a breath or blood sample.
Although some argue that implied consent laws violate your rights against self-incrimination and illegal search and seizure, the justice system has argued that driving is actually a privilege, not a right, and therefore it can be taken away from you. Additionally, because drunk driving has proven to be so dangerous, they believe that it is better to remove drunk drivers from the road without expressed consent rather than allow them to remain a hazard on the roads.
Thus, when you get in the car and turn on the ignition, you are “consenting” through your actions to subject yourself to drunk driving tests should police tell you to pull over. If the circumstances, such as your inability to drive safely, suggest that you are driving while intoxicated, then law enforcement officials can act on implied consent laws and request that you submit a sample for chemical BAC testing.
If you still refuse to consent, the police cannot forcibly extract a sample unless you have caused a serious accident. However, they can still arrest you for “per se intoxication,” meaning that although the police do not know your exact BAC, they have reason to believe that you are a danger to yourself and others due to drunk driving.
After this, your license can be revoked for 180 days. If you have a previous DWI or DUI conviction, this can jump to a 2-year license suspension.
If you have been charged with drunk driving, you are still innocent until proven guilty, and you are still afforded certain rights.