TLDR
- Arizona law does not require you to take the roadside field sobriety tests, and declining them brings no license suspension and no separate charge.
- Officers score three standardized tests, horizontal gaze nystagmus, walk and turn and one leg stand, by counting clues against a fixed cutoff.
- Sober drivers fail these tests because of footwear, road surface, weather, nerves, age, weight and medical conditions, and the scoring sheet accounts for none of them.
- The breath or blood test after arrest is a different question, because implied consent ties a refusal there to a one year license suspension.
What the three roadside tests are and how officers score them
When an officer asks you to step out “for a few tests,” you are being offered the standardized field sobriety test battery. The National Highway Traffic Safety Administration built it decades ago and trains officers to give it the same way every time. Three tests made the cut. The battery exists to support one count in particular, impairment to the slightest degree, the DUI charge that needs no number from a machine.
Horizontal gaze nystagmus. Nystagmus is an involuntary jerking of the eye. The officer holds a pen or fingertip 12 to 15 inches from your face, slightly above eye level, and moves it side to side while you follow with your eyes only. Three clues per eye, six total. The eye does not track smoothly. It jerks distinctly when held at the far corner for about four seconds. The jerking starts before the eye reaches a 45 degree angle. Four clues is the decision point.
Walk and turn. You stand heel to toe with your arms down while the instructions are read, take nine heel to toe steps along a real or imagined line, turn with small steps, and take nine steps back. Eight clues. Losing balance during the instructions. Starting early. Stopping while walking. Missing heel to toe by more than half an inch. Stepping off the line. Raising your arms more than six inches. Turning wrong. Taking the wrong number of steps. Two clues is the decision point.
One leg stand. You raise one foot about six inches, toe pointed out, and count out loud until the officer stops you at 30 seconds. Four clues. Swaying. Using your arms. Hopping. Putting the foot down. Two clues is the decision point.
Those cutoffs are low on purpose. Two small errors on the walk and turn, one of them before you take a step, and the sheet says you failed. The validation studies NHTSA relies on put the eye test near 88 percent accuracy, the walk and turn near 79 percent and the one leg stand near 83 percent, with trained officers under controlled conditions. About one call in five on the walk and turn was wrong before a single Arizona shoulder, pair of boots or set of strobe lights entered the picture.
Why sober drivers fail field sobriety tests
The tests assume a fit adult on a flat, dry, lit surface in flat shoes with no injuries and no fear. The roadside offers none of that.
Footwear. NHTSA’s manual tells officers to give a person in heels over two inches the chance to remove them. Boots, flip flops, sandals and dress shoes all change how a heel to toe step feels, and bare feet on a hot shoulder in July are no better.
Surface and weather. Roads are built with a crown so water runs off, so the shoulder slopes. Gravel, sand, a curved painted line, a rumble strip. Monsoon wind. Dust. Heat over 100 degrees at 9 p.m. Each one pushes a sober person toward a sway or a step off the line.
Lights and traffic. Patrol strobes flash behind you while the officer checks your eyes, and passing headlights sweep across your face. The manual tells officers to face you away from flashing lights during the eye test because the lights themselves make the eye jerk. On a busy highway that step is often skipped.
Nerves. You are on the side of a road at night with an armed officer giving orders and a camera running. Your hands shake and your balance is worse than it was ten minutes ago. Fear does not appear on the scoring sheet as a clue. It appears as a failed test.
Age, weight and medical conditions. The manual states that people over 65, people 50 or more pounds overweight and people with back, leg or inner ear problems had difficulty with the walk and turn and the one leg stand. Add a knee surgery, neuropathy, vertigo or an old ankle injury and the list of people who fail sober gets long. Nystagmus has many causes besides alcohol, including some prescription medications and inner ear disorders.
What Arizona law says about declining the roadside tests
Arizona has no law that requires a driver to perform field sobriety tests. No license suspension attaches to declining them. No fine. No separate charge. Arizona’s base DUI law describes the offense of driving while impaired, and nothing in it makes the roadside tests a duty.
The handheld breath device the officer carries, the portable or preliminary breath test, sits in the same category. It is voluntary at the roadside, its reading supports an arrest rather than serving as evidence of your alcohol level at trial, and Arizona attaches no penalty to declining it.
The test after arrest is a different matter. Arizona’s implied consent rule says that by driving here you have agreed to a breath, blood or urine test once an officer with probable cause arrests you for DUI. Decline that test and the officer serves a notice suspending your license for a year, two years on a second refusal within 84 months, then applies for a search warrant and draws your blood anyway. As of 2026, the window to request the MVD hearing after either notice runs 30 days. The administrative suspension law sets that clock for a failed test, and the request goes through the ADOT Executive Hearing Office. We handle those hearings in-house.
The catch is in the courtroom. Arizona’s appellate courts have let the prosecutor tell a jury that a driver declined the roadside tests, and the prosecutor argues you declined because you knew the result. That argument is answerable. A sober person with a bad knee, a nervous stomach or a lawyer’s advice in mind has every reason to decline a test scored against a two clue cutoff.
Declining does not stop the arrest. An officer who smells alcohol, sees red watery eyes and hears a slurred word will arrest you with or without the tests. What declining removes is a scored test given under conditions you did not control. Police need a reason to pull you over before any of this begins, and our post on what to say and what you are allowed to refuse during a DUI stop covers the rest of the encounter.
The Law Behind This
| Charge or relief | What the law says | What it means for you |
|---|---|---|
| Impaired to the slightest degree | A.R.S. § 28-1381 makes it a class 1 misdemeanor to drive while impaired to the slightest degree, with separate counts for an alcohol concentration of 0.08 or more within two hours and for a listed drug or its metabolite | The roadside tests feed the slightest degree count, so your performance and the conditions around it are evidence the prosecutor leans on |
| Extreme and super extreme DUI | A.R.S. § 28-1382 sets 30 consecutive days of jail at 0.15 or more and 45 days at 0.20 or more on a first offense | These tiers rest on the chemical test result, not the roadside tests, which is why the station test carries far more weight |
| Aggravated DUI | A.R.S. § 28-1383 turns a DUI into a felony when the license is suspended or revoked, when a child under 15 is in the car, or on a third DUI within 84 months | The roadside tests do not change the class of the charge, but the arrest they support opens felony exposure when one of those conditions is present |
| Administrative license suspension | A.R.S. § 28-1385 lets the officer serve a suspension order when the chemical test shows 0.08 or more, and the hearing request must reach the MVD within 30 days of the notice | Declining the roadside tests triggers nothing under this law, while the station test result does, and the 30 day clock starts the night of the arrest |
How declining looks in the police report
The report will say “the driver refused to perform standardized field sobriety tests” or “declined SFSTs.” That line sits inside a paragraph of the officer’s other observations, and those observations do the work the tests would have done. Odor of an alcoholic beverage. Bloodshot, watery eyes. Slurred speech. Fumbling for the license. Officers are trained to write these phrases, and they appear in reports on drivers whose blood later came back under the limit.
How you decline changes that paragraph. “I would rather not do any roadside tests,” said once and politely, gives the officer nothing to add. Arguing, explaining or starting a test and quitting halfway hands the report a new sentence each time.
Body camera changes the math for both sides. Most Arizona agencies record the stop, and the footage shows the words the officer used, whether the request sounded like an order, and how you stood, spoke and walked. A calm driver declining a voluntary test looks different on video than the report makes it sound.
How a DUI attorney takes the roadside tests apart
When you did take the tests, the work is in the details, and the video is where it starts. A lawyer watches the footage against the manual, stage by stage. Did the officer read the full instructions and demonstrate each part? Did the officer ask about injuries, footwear and medical conditions first? Where were the strobes during the eye test? Was the surface flat and dry or a sloped gravel shoulder? Does the report’s “swayed” match the video, or did the officer count a normal shift of weight as a clue? Officers also carry training records, and an officer whose certification has lapsed answers for it on cross examination.
Arizona courts let an officer testify that the eye test showed signs of impairment. They do not let the officer turn a clue count into a specific alcohol number. When the impairment count rests on the tests and the tests fall apart on video, that count becomes winnable.
Two paths follow. The first is a motion to suppress. When the decision to arrest rested mostly on tests that were given wrong or scored wrong, a judge is asked to find there was no probable cause, and if the judge agrees, the breath or blood result taken after the arrest goes out with it. The second is trial. A jury that watches a steady looking driver stand on a sloped shoulder in work boots while strobes flash behind them does not hear “two of eight clues” the way the report reads.
The chemical test still outweighs anything on the roadside, above all at the extreme DUI level where jail is set by the number. That is why we send blood samples for independent retesting instead of accepting the lab report, and why our own lawyers handle the MVD hearing rather than referring it out. Clients get recorded video updates after every court date. Brielle Schumpe leads DUI defense at Future First Criminal Law, Zachary Divelbiss founded the firm, and the team has earned 250+ five-star Google reviews. Fees are flat and published on our pricing page, with payment plans available. Our Arizona DUI lawyers page lays out the full defense approach.
Our Results
The client faced a class 1 misdemeanor DUI charge in a city court with exposure to 180 days in jail, fines above $1,500, a 12 month ignition interlock and probation. We filed our appearance, demanded the prosecutor’s evidence and pressed on each gap in the proof. The prosecutor dismissed the charge in full, with no conviction, no jail and no DUI record. Read the full result.
The client faced two class 1 misdemeanor DUI counts in a municipal court, one for impairment to the slightest degree and one for an alcohol concentration of 0.08 or more. The impairment count is the one roadside observations support, and we pressed the prosecutor on that evidence until the count was dismissed. The client pled to the concentration count alone and received one day served, a fine and an interlock, with no probation. Read the full result.
The client faced an extreme DUI charge in a municipal court with an alcohol concentration between 0.15 and 0.20, carrying nine days of jail on a first offense once the interlock credit is applied, a 12 month interlock and a permanent DUI record. We negotiated the charge down two tiers to reckless driving, a misdemeanor that is not a DUI. The client served zero jail days, paid about $1,650 in fines and monitoring, and finished six months of probation with no DUI on the record. Read the full result. Every case turns on its own record, and past results do not predict a future one.
Talk to a DUI attorney before your first court date
Whether you declined the roadside tests or took them under strobe lights on a gravel shoulder, the report and the video need a lawyer’s eyes before your first court date, and the MVD clock is already running. Call Future First Criminal Law at 602-900-7625. Phones are answered around the clock and consultations are scheduled during business hours. You are welcome to tell us about your case online instead. Our case victories page shows how these cases end.
Frequently Asked Questions
Are field sobriety tests mandatory in Arizona?
No. Arizona has no law requiring a driver to perform the horizontal gaze nystagmus, walk and turn or one leg stand tests. Declining brings no license suspension, no fine and no separate charge.
What happens if I refuse a field sobriety test in Arizona?
The officer notes in the report that you declined and moves on to other observations like odor, eyes and speech. You are still subject to arrest if the officer believes there is probable cause. The prosecutor is allowed to mention the refusal at trial, and your attorney answers with the reasons a sober person declines a test scored against a two clue cutoff.
Is the portable breath test mandatory at the roadside in Arizona?
No. The handheld device is a preliminary screening tool, and Arizona attaches no penalty to declining it. Its reading supports an arrest rather than serving as trial evidence of your alcohol level.
What is the difference between field sobriety tests and the chemical test?
Field sobriety tests happen at the roadside before arrest and are voluntary. The breath, blood or urine test happens after arrest under implied consent, and refusing it costs a one year license suspension on a first refusal while the officer gets a warrant for blood anyway.
How many clues does an officer need to fail me on the walk and turn?
Two clues out of eight. Losing your balance while the officer reads the instructions counts as one, and stepping off the line once counts as another. That is the whole test.
Why did I fail the one leg stand when I was sober?
The test has four clues and two is the cutoff, so one sway plus one arm movement is a failure. Footwear, a sloped shoulder, wind, nerves, age, weight and any back, leg or inner ear problem all push toward those two clues. NHTSA’s own manual lists several of those conditions as reasons the test is hard for sober people.
What is the HGN test looking for?
Nystagmus, an involuntary jerking of the eyes. The officer checks whether each eye tracks smoothly, whether it jerks when held at the far corner, and whether the jerking begins before a 45 degree angle. Four clues out of six is the decision point, and Arizona courts let an officer describe the result as a sign of impairment but not as a specific alcohol number.
How does body camera footage help my defense on the roadside tests?
The video shows the instructions the officer gave, the surface you stood on, the lights behind you and how you moved. A lawyer compares each clue in the report to what the footage shows and challenges each clue the video does not support. When the tests were the main basis for the arrest, that comparison supports a motion to suppress everything that followed.