Standardized Field Sobriety Tests in North Carolina: 2026 Guide
North Carolina DWI evidence guide
Standardized field sobriety tests: what the roadside record should show
The three-test SFST battery has detailed administration protocols. The video, instructions, conditions, medical factors, and officer observations all matter.
Originally published December 27, 2014 · Reviewed and substantially updated September 6, 2026
What SFSTs are designed to do
Officers use standardized field sobriety tests during a DWI investigation to gather observations that may contribute to a probable-cause decision. The National Highway Traffic Safety Administration’s standardized battery consists of horizontal gaze nystagmus, walk-and-turn, and one-leg stand.
These tests are not a medical diagnosis and are not a simple pass/fail exam. NHTSA materials describe specific instructions, demonstrations, timing, scoring observations, and validation conditions. A court evaluates the actual evidence, including whether the tests were administered and interpreted consistently with training.
The three standardized tests
Horizontal gaze nystagmus
The officer positions and moves a stimulus while observing each eye for specified clues. Review stimulus distance and height, equal pupil size and tracking, medical checks, movement speed, maximum deviation, and onset angle.
Walk-and-turn
This divided-attention test includes an instruction phase and walking phase. The officer should provide defined instructions and demonstration, designate a line, and record specific observed clues rather than a general impression.
One-leg stand
The subject is instructed to raise one foot, keep both legs straight, look at the raised foot, and count in a specified way while the officer times the test. Surface, footwear, injury, age, weight, and interruption can matter.
Conditions that can affect performance
| Issue | Questions for the record |
|---|---|
| Surface and space | Was the area level, dry, reasonably smooth, visible, and free from traffic or obstacles? Was there an actual line for walk-and-turn? |
| Instructions | Were instructions complete, demonstrated, and understood? Did the officer interrupt, combine, omit, or change them? |
| Physical and medical factors | Were injuries, neurological conditions, vision issues, medications, footwear, fatigue, anxiety, or balance limitations identified and considered? |
| Recording quality | Does body-camera or dash-camera footage show the feet, eyes, surface, timing, instructions, and full response? |
| Scoring and report language | Does the report identify specific clues, or only conclusions? Are the notes consistent with video and testimony? |
How the evidence should be reviewed
Preserve video early
Identify dash camera, body camera, jail video, booking video, private surveillance, and dispatch recordings. Retention periods can differ.
Compare training to performance
Use the applicable NHTSA manual, the officer’s training history, report, and video to compare what was taught with what occurred.
Connect every observation
Consider driving, the stop, conversation, documents, exit from the vehicle, SFSTs, breath screening, chemical testing, and alternative explanations together.
N.C.G.S. § 20-138.1 defines impaired driving. N.C.G.S. § 20-139.1 addresses chemical analyses and related procedures. SFST observations are one part of the larger evidentiary record; they do not replace proof of each legal element.
What to preserve after a DWI charge
- The citation, charging document, civil-revocation paperwork, and bond conditions;
- all video, audio, photographs, and 911 or dispatch information;
- the officer’s reports, notes, SFST worksheet, training records, and test-device records where available;
- medical records, prescriptions, eyewear information, and evidence of relevant injury or mobility limitation;
- receipts, timeline, witnesses, phone records, and location information; and
- chemical-test records, rights forms, maintenance records, and laboratory materials as applicable.
Continue through the DWI resource center
Official sources
Review the complete record
Roadside details can change the analysis.
Adkins Law represents clients in DWI and traffic matters in Huntersville, Mecklenburg County, and the Lake Norman region.
Legal information only. This article provides general North Carolina information as of September 6, 2026. It is not legal advice and does not create an attorney-client relationship.
Share This Story, Choose Your Platform!
Disclaimer: This website provides general information and discussion about legal topics. The content is not legal advice and should not be relied upon as such. Always seek the advice of a licensed attorney for legal matters.