Wisconsin Drunk Driving Tests

Police must have a legal reason (called probable cause) for stopping you. Under Wisconsin's implied consent laws, they can request you to submit to a blood or breath test; they can even require you to do so (and the courts have upheld forced blood draws in the past). There are several types of tests that can be administered in the field (called standardized field sobriety tests), which do not prove drunkenness. There are also several tests that can be administered that are the basis of proof in testing the level of alcohol in a person's bloodstream, and are usually administered at a hospital. The tests are discussed below.

Standardized Field Sobriety Tests | Chemical Tests | About Blood Tests |
About Refusing A Test | Wisconsin Blood Alcohol Limits |

Standardized Field Sobriety Tests

Standardized field sobriety tests are tests administered by police officers "in the field" when they stop a person suspected of drunk driving. Those tests include:

• Standing on one leg for up to 30 seconds,
• Walk and turn, sometimes administered as heel-to-toe
• Horizontal gaze nystagmus, which may also include vertical gaze nystagmus (the suspect is asked to follow the movement of a penlight)

While the term "in the field" conjures up a vision of a police officer pulling a car over to the side of the highway, the reality is that the stop can occur just about anywhere including in a person's driveway or in a parking lot, with the car or truck running or idle. Just because a police officer stops a person does not mean that the stop was legal, even if the person was arrested. There are many technicalities in drunk driving law, which a highly experienced drunk driving defense attorney immediately recognizes. Regardless of the situation, if you were arrested for drunk driving, you should consult with a DUI defense attorney.

Blood Alcohol Concentration Level Testing

A person's BAC (Blood Alcohol Concentration) level is determined by testing. The results of those tests are used to support prosecution of the person charged with a drunk driving.

Intoximeter - Breathalyzer

A breathalyzer is an Intoximeter. The device requires the alleged drunk driver to blow into a machine. The machine measures the air passing through it to detect the alcohol level.

Intoximeters are usually operated by police officers, who are trained and certified in their usage. The police officers read the test results, and record them in the alleged drunk driver's file. Police officers have been known to make mistakes, misread the results, or record incorrect results. As well, the intoximeter may be out of calibration, thus producing incorrect results. Your drunk driving defense attorney will know what questions to ask and how to determine if any of these situations existed at the time of your arrest.

Do I have to take a breath test?

Under Wisconsin's implied consent laws, police may ask for a blood sample or other test to determine if a suspected driver is drunk according to the law. In other words, they want to measure the percentage of alcohol in the driver's bloodstream.

You can refuse to submit to a test. If you refuse to submit to a test, the law provides for immediate suspension of your driving privileges. Police may also force you to submit to a test, and courts have recognized some forced tests as being valid.

breath tests aren't always accurate and believable

Breath tests aren't always accurate. In fact, some breath tests cannot even be used as evidence in a trial. The so-called "preliminary breath test," or "PBT" is a portable test used by police when they stop a person suspected of driving while drunk. Those tests are not permitted under Wisconsin law.

Any breath test machine can produce inaccurate results. Even the Intoximeter EC/IR, which is the breath testing machine used by the state of Wisconsin as as evidence in court. Breath testing devices are susceptible to a "sampling error." A breath analyzer test measures a person's blood alcohol level. The percentage of ethenol from alcohol that is in a person's bloodstream is the same as the percentage of alcohol on that person's breath when they exhale. Consequently, breath tests devices were developed to test the level of ethenol in a person's exhauled air. During a test, only a small portion of a person's exhauled air is measured - usually only about 81 cubic centimeters. The device then reports a BAC - blood alcohol concentral - level as though all of the exhaled air were tested from the lowest part of the lung, where the only accurate test may be taken of breath. Since the exhaled air must pass through the upper portion of the lung (the brochial tubes) and mouth, where additional ethenol concentrations can be erroneously extracted, the test can result in a false reading that is much higher than the actual concentration levels.

As Attorney Tracey A. Wood points out,

Though machines report test results in terms of 210 liters -- roughly the volume of a 55 gallon oil drum -- they actually only test 81 cubic centimeters of breath -- about the volume of a bathroom size paper cup. In that sample, it takes only about a millionth of an ounce of alcohol in the breath sample -- 0.0000013 oz. -- to get a 0.10 reading. So, even the slightest extra amount of alcohol added to the sample as it is exhaled will give enormously exaggerated results.

Additionally, the Intoximeter EC/IR used for many breath tests in Wisconsin can have engineering and operating defects which make it vulnerable to "radio frequency interference" from police radios and from cellular telephones. Also, the Intoximeter may have been operated with the "slope detector" function -- a safeguard designed into the machine to prevent testing a breath sample contaminated by alcohol from the mouth -- disabled by the Department of Transportation.

Police officers can administer breath tests improperly. A breath test should only be administered after the person has been continuously observed for at least 20 minutes immediately prior to the test to ensure that the person has increased the amount of alcohol in his or her mouth. Vomitting or burping can increase the alcohol levels in the person's mouth.

Just because the machine is used by police and approved by the Department of Transpation doesn't mean that it should be trusted implicitly. While police officers are trained in "how" to use breath test devices, most haven't the slightest clue as to how the breath test devices really work. Perhaps more alarming is the fact that police officers trust the test results.

What is wrong with the breath tester?

Wisconsin has purchased new breath testing machines. These are the Intoximeter EC/IR machines and they replace the Intoxilyzer 5000 in use up in Wisconsin as recently as last year. (Wisconsin doesn't use the "Breathalyzer," and hasn't since the 1970's.)

The Intoximeter EC/IR uses a fuel cell to measure alcohol concentration by converting it to water and electricity.

Recently an official of the Chemical Test Section, Wisconsin State Patrol, Department of Transportation, testified under oath that the Intoximeter EC/IR approved for use in Wisconsin was, in fact, not adequately shielded against "radio frequency" interference. As a result, many machines were taken out of service, and the installation of others was delayed.

"Radio frequency interference" is a common phenomenon -- it's what opens garage doors when, it seems, no one is around. Cellular phones and police radios create radio waves and can cause "RFI."

Even though the State discovered in 1999 that the Intoximeter EC/IR was vulnerable to "radio frequency interference," it did not change its standards for approval of the machines and has refused to disclose testing which it had privately performed after the manufacturer revised the machines.

The decision by Susan Hackworthy, Chief of the Chemical Test Section, to refuse disclosure of this test data, despite requests for the data under the Wisconsin Open Records Law, makes sense only if the data would embarrass the State. If the tests proved that the machine worker properly, both the State and the manufacturer would want the world to know.

The Department of Transportation is now warning police agencies not to operate cellular phones in the same room as an Intoximeter EC/IR, but there is no reason to believe this is an adequate measure to assure that "RFI," from cellular phones or other sources, is not affecting test results.

The problems, however, don't end with "RFI."

Inspection of these machines has revealed that the "slope detector" function has been disabled. This cannot be done by the machine operator. It can only be done by an official from the Chemical Test Section, because the settings of the machine, including the slope detector setting, are password protected.

The "slope detector" is the "IR" part of the machine. The "EC" in Intoximeter EC/IR stands for 'electro-chemical,' i.e., the fuel cell. This is the part of the machine that actually measures the purported alcohol concentration. The "IR" stands for 'infra-red,' and refers to measuring the absorption of infra-red light by the breath sample as it is blown into the machine. This is the "slope detector" function.

This slope detector function, the measurement of the alcohol in the breath sample as it is submitted to the machine, is designed to isolate contaminated breath samples by aborting a test if the alcohol level being blown into the machine exhibits a sudden spike in alcohol level. A spike in alcohol concentration would indicate "residual mouth alcohol" or another source of sample contamination. Disabling the slope detector eliminates the primary design defense of the machine against testing breath samples contaminated with extra alcohol.

If an Intoximeter test is administered on a machine with the "slope detector" operative, the results of testing may not be admissible in evidence in court. Wisconsin law generally allows only machines which are properly operating to be used as courtroom evidence in drunk driving cases.

Chemical Testing - Blood & Urine Tests

Chemical testing includes blood testing and urine testing, and either one or both tests may be administered by hospital personnel.

Blood tests require blood samples drawn from the alleged drunk driver's body (usually from a vein in the person's arm).

Urine tests require the suspect to provide a urine sample. Those samples are delivered into a container while the alleged defendant is in a closely monitored bathroom facility. The water into the bathroom is shut off before the alleged defendant enters the bathroom area, and the door is usually locked preventing anyone from entering or leaving the area.

As with all tests, the administrators must be properly trained in administering that particular test and must record the information correctly.

Drunk Driving Defense Lawyer

If you have been arrested for drunk driving, you must act quickly to save your driver's license. Please call (1-866-262-4599) to speak with an attorney at Van Wagner & Wood right away. Attorney Tracey A. Wood or Attorney Christopher T. Van Wagner will provide you with a brief, but professional free "first-impression" analysis of your drunk driving arrest and information about what you can and must do to preserve your driving privileges.

If you have already been convicted of drunk driving, you may have post-conviction remedies available to you that are often times missed by attorneys who are unfamiliar with prior drunk driving conviction challenges and appeals.

Call 608-284-1200 in Madison, or 1-866-262-4599 statewide