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Understanding Implied Consent Laws and DUI


— November 1, 2019

Most motorists are aware of the dangers of drinking while driving. If at this stage you are still not aware that it is both dangerous and illegal to drink while driving, then you shouldn’t be behind the steering in the first place. 


Implied consent laws can be very tricky to deal with, primarily because the person involved doesn’t expressly grant consent, but the consent is implied by a person’s actions or inactions, or facts and present circumstances surrounding the situation. In some cases, consent can be seen to be implied by a person’s silence. 

Implied consent laws are commonly encountered in the United States drunk driving laws. For instance, an officer of the law can pull you over if he suspects you are driving under the influence of alcohol, and read you an implied consent law before asking you to take a urine, breath or blood test.

For convenience purposes, a breath test can be carried out by the roadside on within a detention facility. Till date, there are no U.S laws that allow implied consent for rape in the court of law. 

Implied Consent laws and Driving While Intoxicated

Most motorists are aware of the dangers of drinking while driving. If at this stage you are still not aware that it is both dangerous and illegal to drink while driving, then you shouldn’t be behind the steering in the first place. 

Most people are also vaguely familiar with the concept of chemical testing that occurs after an individual is been pulled over and arrested for DUI (Driving under the influence). Because of their vaguely familiar concept of chemical testing, most people will refuse to give themselves up for chemical testing. To answer them, most states’ laws have an “Implied Consent” law to take care of a refusing scenario like this.

Criminal defense attorney Patrick O’Keefe explains what an implied consent law is and how it affects you if you are ever arrested for driving under the influence (DUI). 

What are Chemical and DUI Tests All About?

If you have been arrested and charged with a DUI, you will primarily be asked to submit to a chemical test to ascertain if you are really under the influence of alcohol or other controlled substances. Quick chemical test can come in the form of blood, urine and breathe sample tests. While the two former need to be carried out under a testing lab, the later can be done at the roadside or in a detention facility. 

However, implied consent laws do not generally apply to preliminary breath testing hand devices as opposed to evidential breath testing devices. To be used as evidence, the testing instrument must be well calibrated, certified, and administered according to laid down procedures for testing.

During a breath test, the suspect simply blows air into the tube connected to a machine and the blown air is tested for the presence of alcohol. Blood test is a more accurate measurement, but they are the least used because it is considered to be more invasive.

Group of people toasting with snifters; image by Yutacar, via Unsplash.com.
Group of people toasting with snifters; image by Yutacar, via Unsplash.com.

In cases where the arresting officer has enough reason to believe that the suspect is under the influence of controlled substances, a blood test will be ordered because breath testing for drugs is ineffective. Blood testing can also be ordered if the suspect is involved in an accident or if he/she is too intoxicated to perform a breath test. 

Can I Refuse a Chemical Test?

As of today, all states in America have enacted an implied consent law. Let’s summarize the generality of the law in five useful bulleted points:

  • Any person who drives or operates a car will have been seen to have given his consent to submit a blood, breathe or urine sample for the purpose of determining the concentration of alcohol of the presence of controlled substances.
  • An officer on duty is authorized to arrest an individual suspected to be driving under the influence of alcohol or drugs. He is also authorized to read the suspect an implied consent law and collect blood, urine or breath samples for testing.
  • Any person arrested under the influence is mandated to submit a chemical test of his or her blood or urine
  • Any person involved in an auto accident may be required to submit a chemical test of his or her blood or urine by the officer on duty if there is substantial evidence that the accident might have be caused under the influence of alcohol or controlled substances.
  • Refuse to submit or corporate with the peace officer is a crime on its own for which the offending individual can be charged. 

How to Build your Defense

The best way to build your defense if you are ever charged with a DUI is to employ the services of a DUI defense attorney. The most probable action scenario is that the defense attorney will rigorously challenge the implied consent laws which are effective in the location where you were arrested. 

If you are fortunate enough to get advice from defense attorney before you take a chemical test, the advice will most likely instruct you to decline the test and carry out a personal BAC to ascertain if you are truly intoxicated. However, as we have said before, there are penalties for refusing or turning down a test.

In most states, before you apply for a driver’s license you agree through a signed signature form that you will submit to the peace officer’s request to have your blood, urine or breath tested. By law, you are already required to do so before you ever get behind the wheel.

There are arguments for and against signing to such restrictions before you obtain a driver’s license, but in today’s society you can barely get by without it.

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