The Drunk Driving Traffic Stop and Investigation


If you are stopped by a police officer who suspects that you have engaged in drunk driving, you can anticipate that the police are going to ask you questions and investigate your possible intoxication. The following article is meant to provide an overview of what might happen in a typical drunk driving traffic stop.

How Do I Answer The Officer's Questions?

When the police pull a person over, an officer will often ask, "Do you know why I stopped you?" The best answer to the first question, unless the reason is obvious (e.g., you were going 85 mph with a 55 mph speed limit), is usually "No." The officer will explain why he stopped you. If the reason you were stopped is not obvious to you, you may end up confessing to traffic offenses that had nothing to do with why the officer stopped you. However, if the reason is obvious, you look dishonest when you say that you don't know why you were stopped.

Often, the police will also ask, "How much have you had to drink?" You do not have to volunteer any information to the police. If you have been drinking, you may choose to ask a question of the officer, rather than answering, such as, "Are you having problems with drunk drivers around here?" or even, "Why did you pull me over." You may also make a statement, such as, "I really need to get home." But don't assume that the officer is stupid, and if he asks you again don't try to change the subject again. You may refuse to answer if you believe that the truth will make the officer suspect that you are drunk.

What the officer is looking for is evidence that your blood alcohol may be over the legal limit. "I had a glass of wine with dinner," is probably not enough evidence of intoxication unless you are showing other signs of impairment. "I had a couple of beers at a party," may be enough. An answer such as, "I drank a six pack, but that was hours ago," will frequently result in the administration of roadside sobriety tests. If you think your blood alcohol may be over the legal limit and the officer is persistent, you can invoke your right to remain silent or your right to counsel. However, few jurisdictions require that the police give you access to counsel prior to your receiving a breath test, and the police may require that you take sobriety and breath tests even if you refuse to answer questions.

What Happens During The Investigation

Typically, a driver who is suspected of being impaired is required to take roadside sobriety tests, sometimes called "field sobriety tests." These tests may include balance tests (such as bending over or balancing on one foot, often with your eyes closed), reciting the alphabet, counting tests (usually involving counting backwards), and coordination tests (such as walking a straight line, or touching your ring finger to your thumb). Usually, three or four roadside sobriety tests are administered. Please note that if you have any medical conditions that will interfere with your ability to perform roadside sobriety tests, you should tell the officer about those conditions before he administers the tests. Often, drivers dispute the officer's conclusion that they failed some or all of these roadside tests. However, by the time the officer is administering these tests, he has usually already concluded that you are impaired, and is looking for any possible reason to fail you.

If the officer concludes from your performance on the tests that there is reason to believe that you are intoxicated, some states then allow the officer to administer a "preliminary breath test" (PBT), sometimes called a "preliminary alcohol screening test" (PAS), using a portable breathalyzer machine. Subsequent to the roadside testing, if the officer believes you to be impaired, he will typically transport you to the police station where you will ordinarily be given a breath test on a standard "breathalyzer" or "Datamaster" machine.

Can I Refuse To Take Roadside Sobriety Tests, Or A Preliminary Breath Test?

In most jurisdictions you can refuse to take the roadside tests and preliminary breath test without facing any legal consequence for your refusal. However, you should be aware that your lack of cooperation will not necessarily stop the officer from arresting you.

What Changes Are Occurring With Regard To Roadside Drunk Driving Investigations?

The biggest change is the introduction of video cameras on patrol cars and body cameras on police officers. A videotape that shows a drunken, combative driver, or a driver who can barely stand up on his own, is very convincing to a judge or jury, regardless of how a defendant appears in court. It is very difficult to protest that the officer is misinterpreting the roadside sobriety tests when the jury can see the driver's performance, and perhaps even hear what the driver is saying.

Can You Be Ticketed If Your Blood Alcohol Is Below The Legal Limit?

An impaired driving charge can potentially be brought even if your blood alcohol level is below the legal limit.

  • Zero Tolerance Rules for Minors - Many states make it illegal for a minor (any person below the legal drinking age) to have any significant blood alcohol content while driving a car. (The threshold is usually set around 0.02%, to allow for mechanical error and the use of medications or mouthwash, which may artificially inflate the BAC.)

  • You May Be Impaired by a Small Amount of Alcohol - The key issue for prosecution is whether your consumption of alcohol materially impaired your ability to drive. Some people have a low tolerance level for alcohol, and show the effects of intoxication even when they are below the "legal limit." Additionally, if you are taking certain medications, the effects of alcohol can be magnified. The police will sometimes seek a court order for a drug test, particularly if they suspect illegal drug use as the cause of your impairment. However, whether the drugs you take are legal or not, if the net effect of the drugs and alcohol is to substantially impair your ability to drive, you can be charged with "drunk driving."

  • You May Be Impaired from the Use of Drugs or Medication - Some prescription drugs have a material effect on your ability to drive - the warning label on your pill bottle may specifically warn you not to drive after taking your medication. If you ignore this warning, and your driving is impaired by the medication, you can be ticketed for driving while impaired - even though you never consumed alcohol. An officer may also suspect the use of a controlled substance.

When Can The Officer Arrest The Driver?

The officer may arrest the driver when the officer concludes, based upon the totality of the evidence he has observed, that there is probable cause to believe that the driver has an unlawful blood alcohol content, or was driving while impaired. This is a very subjective decision, and it is very difficult to argue that an officer made an illegal arrest, even if you disagree with the officer's conclusions.

When Can The Officer Take The Driver's License?

Most states now allow the police to take the driver's license, upon arresting the driver for an impaired driving offense. The driver may be issued a temporary permit to use until he resolves the drunk driving charge. Every police officer knows what these temporary permits mean, so any person driving with a temporary permit should take great care not to get pulled over again. Some states allow an immediate administrative suspension of the driver's license, which can be appealed through the licensing agency.

When Can I Get An Attorney?

Most states do not require that the police allow you to have an attorney before you have submitted to alcohol testing, or have refused to be tested. Some states allow a consultation with an attorney upon being arrested, before an alcohol test is administered.

What Happens If The Officer Does Not Read Me My Miranda Rights?

In most cases, nothing will happen if the officer does not read you your Miranda rights. If you are arrested, failure to read you your rights may prevent the police from using against you in court the statements you make after your arrest. However, your Miranda rights do not prevent the use of statements you made before you are arrested, most statements you voluntarily make without any prompting from the police, or the use of your alcohol test results.

What Rights Must The Officer Read Me, If I Am Arrested?

The officer must inform you of your chemical test rights. The explanation will typically include a description of what happens to you if you refuse to take a chemical test, and of your right to obtain a blood or urine sample so you can conduct your own test. If the police fail to inform you of the consequences of refusing to take a "chemical test," you may be able to challenge the suspension of your license, resulting from your refusal.

What Happens if I Refuse a Chemical Test While in Custody?

Once you have been arrested for an impaired driving offense you may be required to take a chemical test to determine your blood alcohol content. Prior to testing, you should be informed of your chemical test rights which will typically include a description of the consequences of refusing a test. Consequences typically include serious driver's license sanctions, such as a suspension of your driving privileges. Also, the police may seek a court order to obtain a blood sample from you. If a court issues a warrant authorizing a blood draw, you may be forcibly restrained while a sample is drawn. That usually will occur at a medical facility, but some states have trained police officers to take blood samples from impaired driving suspects.

What Do They Mean By "Per Se" In A Criminal Charge?

Most states allow conviction for drunk driving based solely upon a driver's blood alcohol content. This is called a per se offense. Sometimes, you will be charged both two counts of "drunk driving" (DUI, DWI, or OUIL) - for example, you may be charged with one count of "DUI" and one count of "DUI per se." These alternatives allow the police to argue first that your driving was materially impaired by your alcohol use, and second, even if it was not, that you are guilty solely on the basis of your blood alcohol content. A few states allow conviction for both charges, but you will only be punished for one offense.

A per se offense can only be charged if your blood alcohol content is known.

Can I Represent Myself Against Drunk Driving Charges?

Generally speaking, it is not a good idea to try to represent yourself against any criminal charges. Drunk driving may seem like a relatively minor offense, but it is in fact one of the more complicated criminal charges for prosecutors to bring. There are many technical defenses that an attorney may be able to raise, to assist you either in avoiding conviction, negotiating a lesser charge, or in reducing the consequences of conviction.

Copyright © 2000 Aaron Larson, All rights reserved. No portion of this article may be reproduced without the express written permission of the copyright holder. If you use a quotation, excerpt or paraphrase of this article, except as otherwise authorized in writing by the author of the article you must cite this article as a source for your work and include a link back to the original article from any online materials that incorporate or are derived from the content of this article.

This article was last reviewed or amended on May 26, 2016.