The Tests At The Roadside
ORC 4511.19 — the three standardised tests, and what they are not
Three tests are treated as standardised in Ohio: horizontal gaze nystagmus, the walk and turn, and the one leg stand. The statute makes their admissibility turn on whether they were administered in substantial compliance with the testing standards the arresting agency works to.
- Horizontal gaze nystagmus is the eye test, where the officer moves a stimulus across the field of vision and watches for involuntary jerking.
- The walk and turn is nine heel to toe steps along a line, a turn, and nine back.
- The one leg stand is one foot roughly six inches off the ground while counting aloud.
These are not the chemical test, and implied consent does not reach them. Ohio's implied consent statute is about chemical tests of breath, blood or urine after an arrest. The roadside tests sit before an arrest and are a different thing. The administrative licence suspension that attaches to refusing a chemical test does not attach to these, which is the single most confused point on this subject.
What the results are used for is establishing probable cause to arrest, and then as evidence of impairment at trial. Substantial compliance is the standard the statute sets, so how the test was given is itself a question in the case rather than a formality.
| The question | The roadside tests | The chemical test |
|---|---|---|
| The questionWhen | The roadside testsBefore an arrest, at the roadside | The chemical testAfter an arrest, at the station or a hospital |
| The questionWhat it measures | The roadside testsPerformance the officer observes and scores | The chemical testAlcohol or drug concentration in breath, blood or urine |
| The questionGoverned by | The roadside testsSubstantial compliance with the testing standards | The chemical testThe implied consent statute |
| The questionRefusing carries an administrative suspension | The roadside testsNo | The chemical testYes |
A portable breath device used at the roadside is treated differently from the evidential test taken after an arrest, and Ohio courts have limited what a roadside reading may be used for. That is an argument a lawyer makes on the facts of a case rather than a rule this page can state flatly.
Sources for this section (3)
- ORC 4511.19 — Operating a vehicle under the influence of alcohol or drugs (OVI)
- U.S. Const. amend. IV — Searches and seizures
- ORC 4511.191 — Implied consent to chemical tests
Legal information, not legal advice. Verified as of September 2026. Talk to a licensed Ohio attorney about your situation.