The officer said you “failed” the roadside tests. Did he even give them correctly? That’s where we start.
Jay Cohen is a certified practitioner and instructor of Standardized Field Sobriety Testing, the same NHTSA curriculum police officers train on. When the officer who arrested you takes the stand, he’s cross-examined by someone qualified to teach him the tests. Call (713) 664-4000 and we’ll start with your video.
The only three tests that count
NHTSA recognizes exactly three standardized tests, each with strict administration rules and a fixed list of “clues”:
- Horizontal Gaze Nystagmus (HGN): the eye-tracking test. Six possible clues, and the stimulus must be moved at prescribed speeds and distances. Done freehand on a roadside at midnight with passing headlights? Good luck.
- Walk-and-Turn: eight possible clues, requiring a real or imaginary straight line, proper instructions, and a demonstration.
- One-Leg Stand: four possible clues, timed to 30 seconds. Miscounting the time invalidates the scoring.
The alphabet test, counting backward, touching your nose? Not standardized, not validated. If those show up in your report as evidence of intoxication, that’s an officer padding a weak case.
“Failing” is easier than you think
Even by NHTSA’s own validation studies, these tests are far from foolproof, and that’s when they’re administered perfectly, under controlled conditions. In the real world you were nervous, tired, in bad shoes, on uneven pavement, in traffic wind, maybe with a knee injury or inner-ear issue the officer never asked about. None of that is intoxication. All of it costs you “clues.”
The video doesn’t lie
Nearly every Harris County stop is on camera. We break the footage down frame by frame against the NHTSA manual: Did he instruct and demonstrate correctly? Did he score what actually happened? On a lot of our videos, the person looks fine and the report still says “failed all tests.”
Watch: The field sobriety tests, explained
Short breakdowns of each standardized test, what the officer is scoring, and whether you have to perform them at all.
What are standardized field sobriety tests?
The horizontal gaze nystagmus (eye) test
The walk and turn test
Can you refuse field sobriety tests?
Field sobriety test FAQs
Can I refuse field sobriety tests in Texas?
Yes, roadside tests are voluntary, and refusing them isn’t a crime (unlike test refusal after arrest, which affects your license). If you already took them, don’t worry: taken tests are often our best evidence once the video comes out.
I have a medical condition that affected my balance. Does that matter?
Enormously. Age, weight, injuries, footwear, and certain medications can each produce “clues” that have nothing to do with alcohol, and officers are trained to screen for some of them. If yours didn’t, that’s on the record now.
The officer says I showed all six HGN clues. Now what?
HGN is the most technique-sensitive test of the three, and dozens of conditions besides alcohol cause nystagmus. We’ll match his technique on video against the manual, clue by clue.
Get the instructor on your side
The roadside tests are only one pillar of the State’s case. See how we fight the breath test and the blood test too. Call your Houston DWI lawyer at (713) 664-4000 for a free, confidential consult.
Reviewed by Jay Blass Cohen, founder of Blass Law PLLC, ACS-CHAL Forensic Lawyer-Scientist, certified Drug Recognition Expert, and SFST instructor, serving Houston since 2009. This article is general information, not legal advice for your situation. Prior results do not guarantee a similar outcome.