What is the Implied Consent Law?

With the implied consent law active in some states, drivers should understand the possible penalties of refusing to take field sobriety and breathalyzer tests. Implied consent essentially means consent is assumed even when it’s not expressly given by someone. Rather, it’s inferred from their actions, including silence or lack of effort. Each state has different penalties for breaking the law of implied consent. Read our guide to learn more about implied consent laws in your state.

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UPDATED: Apr 15, 2022

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Written By: Tonya SislerReviewed By: Brad LarsenUPDATED: Apr 15, 2022Fact Checked

In previous years, attorneys would advise people to not submit to a breath test if they had gotten pulled over for suspected drunk driving. Those days have changed with the adoption of the implied consent law, and individuals choosing not to submit to testing should have a clear understanding beforehand of the possible penalties involved for refusal of this testing.

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Implied Consent Defined

An implied consent definition essentially means that which is not expressly given by someone, but inferred from his actions, thoughts or circumstances of the situation, or his silence or lack of action. The implied consent terminology occurs most frequently in the context of U.S. drunk driving laws.

Every state in the U.S. has laws which assert that any licensed driver has given her implied consent to take a field sobriety, breath or similar type of test to determine her level of blood alcohol concentration (BAC) if requested to do so by a police officer. Courts have generally upheld these laws as a valid use of police power.

The Beginning of Implied Consent

Before the implied consent law, two cases made it to the Supreme Court in 1957 and 1966, regarding illegal blood samples taken from drivers after they were arrested for suspicion of driving drunk, and in one case, an accident. The drivers’ consent was not given for either of the blood samples, and the samples subsequently served as evidence to convict one driver of a DUI (driving under the influence,) and another drunk driver of involuntary manslaughter in the death of three people.

The Supreme Court ruled in both of these cases that these individuals’ rights were not violated and that each state should adopt an implied consent law.

Violation of rights

Some drivers have tried to avoid a DUI conviction based on the premise that implied consent laws violate their fourth amendment rights (search and seizure rights ), fifth amendment (privilege against self-incrimination from compelled testimony) and 14th amendment rights (due process.)

The implied consent laws have continued to survive scrutiny many times when challenged on constitutional grounds. Additionally, driving in the U.S. is considered a privilege, not a right, and each state has a legitimate responsibility to keep drunk drivers off the road to prevent property damage, injury or loss of life. Most states, however, do require police to have reasonable grounds established before administering sobriety tests.

Breath tests

A breathalyzer test is performed with a device that estimates BAC from a subject’s breath sample. The Breathalyzer brand name applies to various models of the breath-testing device, originally manufactured by Smith & Wesson. The name has now become a genericized trademark for all devices of this type.

The original device for testing breath was called the drunkometer. Professor Rolla Harger of Indiana University developed it in 1938, and collected the subject’s breath into a balloon held in the device. The breath sample then moved through a solution of acidified potassium permanganate, and if alcohol were present the solution would change color. The more dramatic the color change, the more alcohol contained in the driver’s breath.

Potential errors can happen with any breath tester. The devices tend to have sensitivity to temperature and may give a false reading if not recalibrated or adjusted for the current surrounding temperature. The breathing pattern of the subject can also affect test results significantly. In a study, subjects’ BAC decreased almost 15% after running up a flight of stairs, and almost 25% after running up the stairs twice.

Hyperventilation has shown an ability in studies to lower BAC readings by about 30%, after 20 seconds of hyperventilation. Conversely however, testing also showed if one holds his breath for 30 seconds, his test results will increase by almost 30%. According to research, breath test results can vary 15% or more from an actual BAC. Estimates calculate that around 20% of subjects will have a higher BAC test reading from a breath-testing device than their actual BAC as determined by a blood test.

Test Refusal

Drivers making the choice to refuse a breath test if asked to take one by a police officer will most likely receive some sort of penalty. Drivers still have certain rights, such as their right to be advised of penalties for refusing the breath test, and their right to have the test administered by an independent third party of their choosing. If a subject refuses breath testing, the arresting officer will most likely bring it up during the DUI case in front of the judge.

Officer Information

In most states, police officers have a requirement to inform drivers of the consequences of refusing to take a breath test. An officer must tell the subject of the consequences in the language they speak or understand, as based on a 2007 court case, State v. German Marquez, in which a Spanish-speaking driver in New Jersey did not understand the officer’s request to take a breath test and did not directly respond. The officer considered Mr. Marquez’ lack of response as a refusal, and the court charged him with both a DUI and a breath-testing refusal. After being tried and appealed in the Superior Court, the court ruled that police officers must provide information to subjects in a language they understand.

Penalties for Refusal

Each state has different penalties for breaking the law of implied consent, and refusing to take a breath test. For example, in California any driver who refuses to submit to testing will receive a mandatory license suspension of one year for a first time DUI. A second offender who gets arrested for a DUI within 10 years will receive a mandatory two-year license suspension for the refusal of testing.

In Alabama, a driver who fails to submit to testing will receive an immediate 90-day license suspension. In Massachusetts, refusing to submit to testing will result in a four- month to 12-month license suspension even though the state does not require any immediate license suspension for breath test results. In New York, if a driver refuses testing, he may lose his license for at least one year, and must also pay a $500 penalty in order to get a new license.

Advocates like Mothers Against Drunk Driving (MADD) have made it a point to closely monitor how states persecute drivers who refuse to take breath tests. In fact, MADD estimates that about 20 percent of drunk drivers refuse these tests, and it is the group’s belief that refusals should be “treated as failed sobriety tests.”

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Tonya Sisler has a Bachelor’s Degree from the University of South Carolina in Journalism and has worked for 15+ years in management. She has also completed a proofreading certification and is currently a professional writer.

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Written by Tonya Sisler
Insurance Writer Tonya Sisler

Brad Larson has been in the insurance industry for more than a dozen years. He started out as a claims adjuster for a national carrier. He has since switched to the agency side of the business. Brad is licensed in all P&C lines.

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Reviewed by Brad Larsen
Licensed Auto Insurance Agent Brad Larsen

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