Reasons Standard Field Sobriety Tests are unreliable

While standardized field sobriety tests (SFSTs) are commonly used to determine possible DUI, scientists who study the issue have claimed that “not a single study” links SFSTs to driving impairment. Despite this fact, such tests are often used at roadside and play a role in many DUI citations. If you have failed an SFST, an Orange County DUI lawyer may be able to help you defend your case.

The National Highway Traffic Safety Administration (NHTSA), the United States Department of Transportation, and the NHTSA-commissioned researchers do not claim that standardized tests are indicators of driving impairment. These organizations specifically point out the limitations SFSTs. They note that driving a motor vehicle is a complex activity and that tests measuring one’s ability to operate a motor vehicle are unlikely to be accurately measured at roadside. In fact, according to one study, “even valid, behavioral tests are likely to be poor predictors . . . of actual behind-the-wheel driving.” An experienced DUI defense lawyer can help you cast doubt on the efficacy of the roadside test administered to you.

Moreover, some police agencies do not believe that all SFSTs are accurate. For example, the California Highway Patrol Manual states that the horizontal gaze nystagmus test (HGN) is not meant to be a psychosocial test and the associated clues are not designed to discover signs of impairment. Yet, your DUI citation may very well have been based, at least in part, on your “failure” of an HGN test.


If you are not currently represented by a lawyer, please contact the law office of Chad Maddox at (714) 547-4500, for a free consultation with an experienced Orange County DUI attorney. A list of 'recent victories' achieved by his office can be found at www.gototrial.com/recent-victories.