Factors That Can Influence a Field Sobriety Test

Field sobriety tests are commonly administered by an arresting officer to determine whether a person has been driving under the influence of alcohol or drugs. There are three typical field sobriety tests, the Horizontal Gaze Nystagmus, Walk and Turn, and One Leg Stand tests. Evidence of your failure to perform these tests to an expected level could serve as grounds for your arrest and may lead to your ultimate conviction for DUI. Field sobriety tests, however, are susceptible to many failings. A wide array of physical and external factors can influence a field sobriety test, leading to inconclusive results. DUI defendants can challenge the results of a flawed field sobriety test to potentially avoid conviction.

Physical Factors

Standards for administration of field sobriety tests can be found in the Standardized Field Sobriety Testing Manual created by the National Highway Traffic Safety Administration. Georgia law requires that field sobriety tests be administered in a consistent and reliable manner, but the results of a field sobriety test cannot be trusted when certain physical or external factors exist. Physical factors that could influence the outcome of a field sobriety test include:

1. Injuries: Individuals who suffer from back issues, leg pain, mobility problems, and inner ear conditions could all experience difficulty when performing a field sobriety test. The Walk and Turn test and One Leg Stand require accurate balance, which those with certain injuries or conditions will not have. Further, the Horizontal Gaze Nystagmus may not offer accurate results for those with a seizure disorder or certain eye conditions.

2. Age: Those over the age of 65 may struggle to perform field sobriety tests even when completely sober. The results of the One Leg Stand and Walk and Turn test cannot be considered accurate where the person arrested is physically incapable of completing the test to the desired level.

3. Weight: Individuals who are more than 50 pounds overweight could struggle with some of the field sobriety tests. Discrepancies that an officer might attempt to attribute to alcohol could, in fact, stem from physical qualities of the defendant.

External Factors

Along with a person’s physical characteristics, there are several external and environmental factors that can influence a field sobriety test. For example, slick or uneven road conditions could render the results of the Walk and Turn or One Leg Stand test inaccurate, as less than ideal road conditions may cause the suspect to slip or falter. Bright sunlight could impact the Horizontal Gaze Nystagmus test. Anyone who is facing DUI charges based on a failed field sobriety test should contact a DUI defense lawyer to start protecting their legal rights today.