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DUI Drunk Driving Field Sobriety Testing


There are a number of ways a police officer can try to determine if he or she should make a DUI arrest. The officer will likely ask you a number of questions in order to assess your current condition so that they can use their best judgment in order to proceed with further tests, or to let the driver go on their way. Typically these tests will include coordination, balance, and attention challenges such as:

  • Writing the alphabet or saying it backward
  • The “Rhomberg test,” or “modified position of attention”
  • One leg stand
  • Horizontal gaze (Nystagmus, or following a pen or other object from side to side with only your eyes)
  • Walk and turn (Walking a straight line, heel to toe, turning, then walking back heel to toe.
  • Touching your nose
  • Divided attention tests, such as having you retrieve your license while asking you questions
  • Counting fingers
  • Hand clap tests, requiring you to count and increase your clapping speed
  • PAS test (Preliminary Alcohol Screening test) A handheld breath test often give after the above tests

Other symptoms that lead to arrest

The officer can also use other evidence to determine if they should arrest a driver for a potential DUI charge. Driving erratically, slurred speech, dilated pupils, bloodshot eyes, odor of an alcoholic beverage, vomiting, and incriminating statements can also lead an officer to order a person to submit to a roadside chemical test. After an officer arrests you for DUI, you are required to take a chemical test of risk losing your license for at least a year.

Problems with field sobriety tests
It is important to remember that people who are not under the influence of drugs and/or alcohol can have difficulty passing these tests. Many scientific studies have questioned the accuracy of these tests, and drivers are not required to take these tests. Respectfully declining to take these tests gives the prosecution less evidence to use to convict you of drunk driving. The only tests you are required to take are the evidential chemical tests usually administered at the police station, jail, or hospital.

Some common problems that can negatively affect the outcome of your field sobriety test include:

  • There are no standards of comparison for performance; that is to say there is no way to determine what is the normal amount of coordination or balance of the subject. Some people are just clumsy, but this should not send them to jail.
  • Some illnesses and other medical problems can affect balance and coordination
  • Test anxiety can affect performance as well. People taking roadside sobriety tests are often nervous, and the presence of a police officer and the threat of arrest can make even simple actions complicated.
  • Most of the tests themselves such as hand pat, alphabet, and finger-to-nose have not been sufficiently tested to determine if they are accurate measures of intoxication.
  •  The size, age, and gender of the subject often affect mental and coordination abilities.
  • The roadside or police station environment is often intimidating and full of distractions; other people, cars driving past, the weather, the ground itself can all have adverse effects on the subject.
  • The tests are rarely administered or evaluated in the way the National Highway Traffic Safety Administration (NHTSA) deems correct and proper.
  • The tests are often based on subjective interpretation rather than objective standards.
  • The Federal government sponsored studies that have admitted there is no direct correlation between a particular performance on a standardized field sobriety test (SFST) with driving impairment

Problems with roadside chemical tests in the Bay Area

Each chemical test is fallible in any number of ways. They require precisely maintained and calibrated instruments that are subject to a number of variables that can influence their outcome in favor of the prosecution. Unless your DUI attorney is familiar with the procedures and potential problems associated with each of these tests you could face any number of penalties that could possibly have been otherwise dismissed. Here are some issues or situations that can affect chemical testing:

  • Temperature of the person being tested
  • The temperature of the machine
  • Breathalyzers are supposed to test if people have a 2100/1 blood to breath ratio. In fact, ranges between 1100/1 to 3200/1 have been measured, making these results suspect at best
  • Diabetes
  • Fasting or dieting
  • Some types of breads
  • Smokers have higher contents of acetaldehyde, a chemical that can register on a breathalyzer but is not the result of recent alcohol consumption
  • Alcoholics that have not been drinking tend to have a higher concentration of acetaldehyde in their system as well
  • GERD (Gastroesophogeal Reflux Disease) This disease can cause false positives to occur in breath measuring tests

If you are charged with Driving Under the Influence in the Bay Area, you must take action immediately. The first thing Aaron Bortel tries to do is win your case. We understand your pain, and know that you want to put this ordeal behind you as quickly as possible. Aaron Bortel exclusively handles Bay Area DUI cases, and knows the confusion, fear, and frustration you are feeling right now, and working together, he can take on the courts and the DMV and get you back on the road today.

Aaron Bortel

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