The DUI Stop
Idaho Code § 18-8004 and Idaho Code § 18-8002 — 0.08, consent deemed given to testing, and a $250 civil penalty for refusing
It is unlawful to drive or be in actual physical control of a motor vehicle while under the influence of alcohol, drugs or other intoxicating substances, or with an alcohol concentration of 0.08 or more, on a highway or on public or private property open to the public. Actual physical control is being in the driver's position with the motor running or the vehicle moving.
Consent is deemed given. A person who drives in Idaho is deemed to have consented to evidentiary testing at the request of an officer with reasonable grounds.
- Refusing a test brings a civil penalty of $250, and a suspension of one year for a first refusal and two years for a second within ten years.
- A driver who refuses may request a hearing within seven days, to show cause why the test was refused.
- An ignition interlock follows for one year after a refusal suspension.
Those are the consequences of refusing, and the hearing is limited to that question, with the burden on the driver.
- A first offense: a misdemeanor, up to six months and a fine of up to $1,000, a thirty day absolute suspension followed by more, and an ignition interlock.
- A first offense at 0.20 or more: at least ten days in jail, up to one year, and a fine of up to $2,000.
- A second offense within ten years: at least ten days in jail, the first forty-eight hours consecutive, up to one year, a fine of up to $2,000, and a one year absolute suspension after release.
- A third offense within ten years: a felony, up to ten years and a fine of up to $5,000.
Those are the penalties the sections set.
Testing is also limited by the Fourth Amendment. The Supreme Court of the United States has held that a breath test may be taken without a warrant as part of a lawful arrest for drunk driving and a blood test may not; that a driver may not be criminally punished for refusing a blood test where no warrant was obtained; and that the natural fall of alcohol in the blood does not by itself create an emergency excusing a warrant in every case, which is decided case by case on all the circumstances. Those holdings are a floor: a state's own constitution and statutes can give more protection than they do, never less.
A test result under 0.08 does not end a prosecution for drugs. An administrative suspension for failing a test runs through the transportation department on its own clock. A particular case is a question for a licensed Idaho attorney.
Sources for this section (6)
- Idaho Code § 18-8004 — Persons under the influence of alcohol, drugs or any other intoxicating substances
- Idaho Code § 18-8005 — DUI penalties
- Idaho Code § 18-8002 — Tests of driver for alcohol concentration, penalty and suspension upon refusal
- Idaho Code § 18-8004C — Excessive alcohol concentration, penalties
- Birchfield v. North Dakota, 579 U.S. 438 (2016) — A breath test may be taken incident to arrest, a blood draw needs a warrant
- Missouri v. McNeely, 569 U.S. 141 (2013) — The natural fall of blood alcohol is not by itself an emergency justifying a warrantless draw
Legal information, not legal advice. Verified as of October 2026. Applying it to a particular situation is the work of a licensed Idaho attorney.