SFST Test Administration 2 — Questions and Answers
Question 1: When administering the HGN test, what is the correct speed for moving the stimulus across the subject's visual field during smooth pursuit?
- As fast as the subject's eyes can follow
- Approximately 2 seconds from center to side (Correct answer)
- Approximately 4 seconds from center to side
- The officer determines speed based on subject's impairment level
Correct answer: Approximately 2 seconds from center to side
NHTSA standardizes smooth pursuit passes at approximately 2 seconds from center to the side of the visual field.
Question 2: Which condition would make it inappropriate to use the Walk-and-Turn test on a subject?
- The subject is wearing athletic shoes
- The subject is over 65 years of age (Correct answer)
- The subject is a licensed driver
- The subject denies alcohol consumption
Correct answer: The subject is over 65 years of age
NHTSA notes that subjects over 65, those with leg injuries, or those with inner ear disorders may have difficulty with the WAT regardless of impairment.
Question 3: During the One-Leg Stand, which clue is recorded when the subject puts their raised foot down before the count is complete?
- Swaying
- Hopping
- Puts foot down (Correct answer)
- Uses arms for balance
Correct answer: Puts foot down
Puts foot down is the specific NHTSA clue recorded when the subject lowers their raised foot before being instructed to stop.
Question 4: What is the NHTSA-standardized count duration for the One-Leg Stand test?
- 20 seconds
- 25 seconds
- 30 seconds (Correct answer)
- 45 seconds
Correct answer: 30 seconds
The subject is instructed to count aloud while standing on one leg for 30 seconds per NHTSA protocol.
Question 5: When positioning a subject for field sobriety tests at night, the officer should ensure:
- The subject faces oncoming traffic for visibility
- Headlights are turned off to avoid glare affecting HGN
- The subject is on a level, non-slippery surface away from traffic (Correct answer)
- Tests are administered inside the patrol vehicle for safety
Correct answer: The subject is on a level, non-slippery surface away from traffic
NHTSA requires a reasonably level, non-slippery surface away from traffic hazards for valid and safe test administration.
Question 6: During the HGN test, at what angle from center does the officer check for distinct and sustained nystagmus at maximum deviation?
- At 30 degrees
- At 45 degrees
- At 60 degrees
- At the point where the iris is no longer visible (Correct answer)
Correct answer: At the point where the iris is no longer visible
Maximum deviation is reached when the eye has moved as far to the side as possible, indicated by the iris being at or near the corner of the eye.
Question 7: If a subject refuses to perform all three standardized field sobriety tests, the officer should:
- Release the subject since no evidence was gathered
- Document the refusal and rely on other observed indicators (Correct answer)
- Physically force the subject to complete the tests
- Administer only the HGN since it requires no subject cooperation
Correct answer: Document the refusal and rely on other observed indicators
A refusal is itself significant and should be documented; officers rely on other behavioral and observational evidence to support probable cause.
SFST Test Administration 2
When administering the HGN test, what is the correct speed for moving the stimulus across the subject's visual field during smooth pursuit?