There are limits to when a police officer can demand that you perform a chemical breath test even if they suspect you of drunk driving. If you caused a collision, an officer can generally demand the test as part of their investigation.
However, the standard is different during a traffic stop. An officer who pulls you over because they think you might have had too much to drink cannot instantly demand that you perform a breath test or arrest you right away.
Typically, the officer conducting a driving under the influence (DUI) traffic stop will ask the driver to perform a field sobriety test. What is the point of those physical tests?
Field sobriety tests help establish probable cause
Without your consent, a police officer needs probable cause to perform a chemical breath test. They need that and other evidence for a prosecutor to pursue charges against you. Simply noticing erratic driving might not constitute probable cause, as there could be many explanations other than intoxication.
Field sobriety tests involve having a driver perform basic physical tasks that can help an officer gauge their potential chemical impairment. By asking a driver to talk and turn, stand on one leg or follow a moving finger with their eyes, an officer can check a driver for common indicators of chemical impairment.
Poor performance on one or more of these tests might lead to an officer requesting a breath test and then arresting the driver involved. Understanding the process during a drunk driving traffic stop can help you decide on the best defense strategy for your case.