Field Sobriety Testing and Its Deficiencies
When a driver is suspected of being under the influence of drugs or alcohol, law enforcement officers will often ask that individual to submit to a series of field sobriety tests. These tests, however, are not always a reliable indication of a person’s level of intoxication. When an individual is asked to submit to this form of testing, knowledge of the law is crucial. These tests are voluntary and, at least in Illinois, there is no penalty for refusing to submit to field sobriety testing.
In the late 1970s, the National Highway Traffic Safety Administration (NHTSA) commissioned the Southern California Research Institute, and its director, Marcelline Burns, to begin conducting research into the possible development of a battery of standardized field sobriety tests. Though six tests were used in the initial stage, only three of those tests were ultimately determined to be sufficiently reliable and accurate to conduct further studies in the field. Those tests include:
(1) horizontal gaze nystagmus (HGN);
(2) one-leg stand (OLS); and
(3) walk-and-turn (WAT).
These are now the standard tests used by law enforcement officers in drunk driving investigations, otherwise known as the standardized field sobriety tests (SFSTs).
But even Dr. Macelline Burns, who approved these tests as a sufficiently reliable means of determining a person’s level of intoxication, has acknowledged that there is no correlation between performance on the SFSTs and the operation of a motor vehicle. In one study, for example, 21 individuals were videotaped performing the SFSTs, as well as a set of “normal abilities” tests. 14 police officers were then asked to view the videotapes and make a determination about the individual’s level of intoxication. The officers concluded that 46% of the individuals had “too much to drink.” In fact, all 21 participants had performed the tests with a 0.00 blood alcohol concentration. Spurgeon Cole and Ronald H. Nowacxyk, Field Sobriety Tests: Are They Designed for Failure?, 79 Perceptual & Motor Skills 99 (1994).
The false positives from the study indicates that police officers are incapable of properly determining someone’s level of intoxication because of poor training or a preexisting bias. Although the NHSTA has laid out very specific steps for the proper administration, assessment, and interpretation of the SFSTs. Nonetheless, officers will frequently negligently, deliberately or incompetently administer the Field Sobriety Test which then allows them to conclude that the driver is intoxicated. For example, there are 10 steps in the systematic administration of the Horizontal Gaze Nystagmus test.
Even if the officer follows all 10 steps in properly administering the test, however, the officer must then properly score and interpret the test according to specific clues. And, even if the officer properly administers the test, properly scores the test, and properly interprets those results, independent factors can affect the validity of the officer’s interpretation, including certain medical conditions, which may render the same results as if the individual were intoxicated.
Given the numerous uncontrolled variables that apply in determining intoxication in the field, drivers should hesitate in agreeing to undergo a field sobriety test in Illinois.
