Police officers often request chemical breath tests when they want to prove that someone has driven while drunk. It is common for officers to request breath tests during a traffic stop or while they put together a report following a collision.

Drivers often feel flustered and uncertain about chemical testing during an interaction with a police officer. They can make mistakes that may leave them at a disadvantage later if the officer arrests them. Drivers generally need to know the basics about chemical breath tests to adequately assert themselves when interacting with law enforcement.

What do drivers need to know about breath tests?

False positives are surprisingly common

There are a host of different reasons why chemical breath tests might produce inaccurate results. Medical issues on the part of the driver can compromise test accuracy. So can issues with device maintenance or calibration. False positives and elevated readings are so common that some courts do not allow breath tests as the main source of evidence in an impaired driving case.

A failed test is a crime on its own

Police officers don’t need to prove that someone drove poorly and was over the legal limit to justify their arrest. Simply having an elevated blood alcohol concentration (BAC) is enough to warrant arrest and prosecution. The statute establishing a limit for a driver’s BAC makes an elevated BAC a per se offense. Being over the legal limit is illegal even if there is no proof that the alcohol affected someone’s driving ability.

Refusing a test can also have consequences

Those concerned about false positives might want to refuse a test when an officer asks them to perform one. Unfortunately, doing so is also a crime. The implied consent statute makes it a secondary criminal offense to refuse a chemical breath test where the police officer already has reason to arrest a driver. The courts may impose an additional license suspension when sentencing motorists who violated the implied consent law. An officer can also talk about the refusal to perform testing as part of a drunk driving trial.

Learning about implied consent rules and breath testing in general can help people better handle a traffic stop. Some motorists can fight impaired driving charges by raising questions about test accuracy or convincing the courts that a traffic stop was illegal.