Field Resource

Standardized Field Sobriety Exercises

Florida SFST/FSE: HGN, Walk-and-Turn, and One-Leg Stand

Expand each section as needed. Administer and interpret these exercises according to current FDLE/NHTSA training and agency policy.

1. Prepare, Screen & Document

Select the location

Maintain officer, subject, and roadway safety.
Use the best available reasonably dry, hard, level, well-lit, and non-slippery surface.
Note traffic, weather, lighting, surface conditions, footwear, and unavoidable deviations.

Ask before beginning

Record each response for this session.

Are you sick or injured?
Are you Diabetic / Epileptic?
Do you take insulin?
Are you under the care of a doctor or dentist?
Are you taking any medications?
Do you have a physical handicap?

Offer an opportunity to remove unusual footwear when safe and appropriate.

Document

The subject's answers or denial of limitations.
Visible injuries, mobility aids, balance problems, footwear, communication difficulties, and other observed limitations.
Whether an exercise was modified, stopped, omitted, or performed under less-than-optimal conditions.

A medical condition or medication does not, by itself, prove impairment.

2. Horizontal Gaze Nystagmus — HGN

Position and preliminary checks

Have the subject remove glasses, if applicable.
Hold the stimulus approximately 12–15 inches from the nose and slightly above eye level.
Tell the subject to keep the head still and follow the stimulus with the eyes only.
Check equal pupil size, resting nystagmus, and equal tracking.

6 standardized clues

Check each eye separately for:

Left eye — lack of smooth pursuitRight eye — lack of smooth pursuitLeft eye — distinct and sustained nystagmus at maximum deviationRight eye — distinct and sustained nystagmus at maximum deviationLeft eye — onset of nystagmus prior to 45 degreesRight eye — onset of nystagmus prior to 45 degrees

There are 3 possible clues in each eye. Check vertical gaze nystagmus as trained and document it separately.

Administration reminders

Check the left eye first, then the right, and repeat each pass as trained.
Hold at maximum deviation for at least four seconds.
Move the stimulus slowly when checking for onset before 45 degrees.
Record each clue separately for each eye.

3. Walk-and-Turn — WAT

Instruction stage

Give instructions and demonstrations from a safe position.
Place the left foot on the line.
Place the right foot directly in front of the left, heel-to-toe.
Keep both arms at the sides and hold that position.
Do not begin until instructed; confirm the subject understands.

Walking stage

When told to begin, step with the left foot heel-to-toe in front of the right and count that walking step as "one."
Take nine heel-to-toe steps, watch the feet, and count each step aloud.
Leave the lead foot on the line and complete the demonstrated series-of-small-steps turn with the other foot.
Return with nine heel-to-toe steps while counting aloud.
Keep arms at the sides and do not stop after beginning.

8 standardized clues

Document each clue and when it occurred.

4. One-Leg Stand — OLS

Instruction stage

Give instructions and demonstrate from a safe position.
Stand straight with feet together and arms at the sides.
Do not begin until instructed; confirm the subject understands.

Balance and counting stage

Raise either foot approximately six inches off the ground.
Keep the raised foot parallel to the ground and both legs straight.
Look at the elevated foot.
Count aloud: "one thousand one, one thousand two, one thousand three," until told to stop.
Time the exercise for 30 seconds.

4 standardized clues

Which Leg Raised?

Sways while balancingUses arms to balanceHopsPuts the foot down

Document each clue, how often it occurred, and whether the subject restarted or could not complete the exercise.

OLS — 30-second timer

00:30

Ready

Timing aid only. Keep this screen visible and follow approved OLS procedures. The timer resets when you leave this page or reload.

Export exercise results

HGN, Walk-and-Turn & One-Leg Stand

HGN 0/6WAT 0/8OLS 0/4

Boxes checked · Raised leg: Not selected

Review all checkbox results

2. Horizontal Gaze Nystagmus — HGN

Not checked: Left eye — lack of smooth pursuit
Not checked: Right eye — lack of smooth pursuit
Not checked: Left eye — distinct and sustained nystagmus at maximum deviation
Not checked: Right eye — distinct and sustained nystagmus at maximum deviation
Not checked: Left eye — onset of nystagmus prior to 45 degrees
Not checked: Right eye — onset of nystagmus prior to 45 degrees

3. Walk-and-Turn — WAT

Not checked: Cannot keep balance while listening
Not checked: Starts too soon
Not checked: Stops while walking
Not checked: Does not touch heel-to-toe
Not checked: Steps off the line
Not checked: Uses arms to balance
Not checked: Makes an improper turn
Not checked: Takes an incorrect number of steps

4. One-Leg Stand — OLS

Raised leg: Not selected

Not checked: Sways while balancing
Not checked: Uses arms to balance
Not checked: Hops
Not checked: Puts the foot down

Unchecked boxes do not establish that a clue was absent. This summary records selections only; it does not determine impairment or replace agency documentation.

Choose an email app from your device’s share menu. If unavailable, save the PDF and attach it manually.

Generated on your device. Results are not uploaded to the Field Guide. Saved or shared copies remain outside this session.

5. Evaluate the Totality

SFSTs are investigative tools and should not be treated as an isolated pass/fail decision. Consider and document:

Vehicle-in-motion observations
Initial contact and divided attention
Statements and admissions
Odor and physical indicators
Exit-sequence observations
Medical and physical limitations
Environmental conditions
Each standardized clue observed
Any inability, refusal, modification, or deviation
Body-worn camera and other lawful evidence

6. Official Sources & Important Notice

FDLE CJSTC-13 Performance Evaluation FDLE Basic Recruit Training Curriculum NHTSA SFST Training Resources

Use current FDLE/NHTSA training, current law, and agency policy. This field resource is a quick-reference aid and does not replace certified training or legal guidance.