Law enforcement officials have traditionally utilized field sobriety tests (FSTs) as a means to evaluate driver impairment. Although their accuracy has been questioned at times, these tests can offer valuable insights, especially considering the limitations of blood and breath tests. Combining FSTs with blood or breath tests may provide the most accurate assessment of impairment.
FSTs encompass various forms, including:
Horizontal gaze nystagmus: This test detects involuntary eye movements that are imperceptible to the intoxicated individual. According to a study published in the journal WIREs Forensic Science, this test is unreliable unless alcohol consumption is also involved.
One leg stand: This test assesses the ability to maintain balance on one leg and can indicate heavy drug use.
Modified Romberg balance: A unique test that reveals issues with time perception and physical impairments. Test takers stand with their feet together while tilting their heads back and must maintain this position for thirty seconds.
Walk and turn: One of the most recognizable FSTs, it determines whether drivers can walk in a straight line.
Advancements in testing have taken FSTs to the next level. Neurocognitive tests now promise to assess the degree of impairment in drivers' executive function.
DRUID (Driving Under the Influence of Drugs), a Massachusetts company, has developed a mobile app that evaluates hand-eye coordination. Initially designed as a personal assessment tool to prevent intoxicated individuals from driving, this app's potential usefulness extends to law enforcement as well.
Another test called AlertMeter may distinguish between everyday consumption and genuine impairment. Initially proposed for employee drug testing, AlertMeter could also be beneficial in verifying whether drivers with detectable levels of THC are capable of safely operating vehicles.
Field sobriety tests continue to play a crucial role in evaluating driver impairment. While their accuracy is not flawless, combining them with other testing methods and incorporating advancements in neurocognitive assessments may enhance their effectiveness in ensuring road safety.
