If police suspect you of DUI, your job in the next few minutes is narrow: pull over safely, hand over your license and registration, stay polite, and decline to answer questions about what you drank or used. Field sobriety tests and the handheld roadside breath test are voluntary for most adult drivers. The chemical test after arrest is not, and refusing it triggers an automatic license suspension in every state.
The First Minutes at the Window
Pull over as soon as it is safe. Turn on your interior light if it is dark. Keep both hands on the steering wheel until the officer reaches your window, and do not reach into your glove box or center console until you are asked to. Officers approaching a car at night are assessing threat level before anything else, and visible hands lower the temperature of the encounter immediately.
Officers begin evaluating you before you roll down the window. Weaving, drifting onto the shoulder, wide turns, and erratic braking are the driving patterns that typically trigger a stop. Once you are stopped, they look for bloodshot or glassy eyes, slurred speech, fumbling with documents, and the smell of alcohol or marijuana. No single observation proves impairment, but officers are trained to stack them.
What You Must Give the Officer and What You Can Decline
You are required to hand over your driver’s license, registration, and proof of insurance. That is the end of what you must provide. The Fifth Amendment protects you from being forced to answer questions that could incriminate you.1Federal Law Enforcement Training Centers. Miranda and the 5th Amendment
“Have you been drinking tonight?” is the most common question at a DUI stop, and you do not have to answer it. A polite “I’d prefer not to answer questions” is enough. Do not lie, because a false answer creates its own problems, but silence on incriminating questions is your right. Avoid statements people wrongly think will help them. “I only had two beers” is not the exculpatory line it sounds like; it is an admission of drinking that the officer will write down.
One point most drivers get wrong: officers do not have to read you Miranda warnings during the roadside phase. Miranda applies to custodial interrogation after arrest. The questions at your window, the field sobriety tests, and the preliminary breath test all happen before custody, and your responses during that phase are generally admissible whether or not you heard any warning. This is where most people unknowingly provide the strongest evidence against them.
The Sixth Amendment right to an attorney does not attach at the moment of a traffic stop either. It kicks in when formal judicial proceedings begin, at a preliminary hearing, arraignment, or formal charging.2Constitution Annotated. Amdt6.6.3.1 Overview of When the Right to Counsel Applies You have no right to call a lawyer before deciding whether to take field sobriety tests or a preliminary breath test. Even after arrest, whether you can consult an attorney before a chemical test varies by state, and in many places waiting too long for a lawyer is treated as a refusal under implied consent laws.
Field Sobriety Tests Are Voluntary
If an officer suspects impairment, the next step is usually a request to perform standardized field sobriety tests at the roadside. There are three: the Horizontal Gaze Nystagmus test, where the officer watches your eyes track a pen or light for involuntary jerking; the Walk-and-Turn; and the One-Leg Stand.3National Highway Traffic Safety Administration. DWI Detection and Standardized Field Sobriety Testing SFST Participant Manual
Here is what most drivers do not know: for adults over 21 who are not on DUI probation, these tests are voluntary. You can politely decline. Refusing them does not carry a direct legal penalty like license suspension, and the refusal by itself does not give an officer enough to arrest you. An officer who already saw you swerving and smelled alcohol on your breath may arrest you anyway on those observations, but declining the tests removes one piece of evidence from the case.
Officers may also ask you to blow into a handheld breathalyzer at the roadside, sometimes called a Preliminary Alcohol Screening device. For most adult drivers this is also voluntary, and declining does not trigger the same penalties as refusing a post-arrest chemical test. Drivers under 21 and those on DUI probation are the exception. For them the preliminary breath test is mandatory, and refusing can bring a license suspension.
The decision whether to perform field sobriety tests is a judgment call. If you are confident you are sober, performing them may end the encounter. If you are not confident, the tests will generate evidence you cannot take back.
After Arrest: Implied Consent Changes Everything
The voluntary phase ends at arrest. Once you are lawfully arrested for suspected impaired driving, you will be asked to submit to a chemical test of breath, blood, or sometimes urine. Breath tests at the station use more precise equipment than the roadside device, and blood draws give the most accurate reading of what is in your system.
Every state has an implied consent law. By driving on public roads, you have already agreed in advance to take a chemical test if you are lawfully arrested for impaired driving. Refusing that post-arrest test triggers automatic administrative penalties whether or not you are ever convicted of a DUI. The most common is a license suspension of at least one year for a first refusal, with longer suspensions for repeat refusals. The motor vehicle department imposes these suspensions, not the court, and they proceed even if the criminal case is dismissed. Prosecutors can also tell a jury you refused and argue the refusal shows you knew you would fail.
Blood Tests Require a Warrant
The Supreme Court drew a line in Birchfield v. North Dakota. Warrantless breath tests after a DUI arrest are constitutional, but warrantless blood tests are not. Because a blood draw pierces the skin and produces a sample that can be stored and analyzed for far more than alcohol, the Court found it too invasive without a warrant. A state can impose civil penalties for refusing a breath test, but it cannot make it a crime to refuse a blood test unless officers first obtain a warrant.4Justia US Supreme Court. Birchfield v. North Dakota
Many jurisdictions now run “no-refusal” enforcement initiatives around holidays and major events, with prosecutors and judges on standby so officers can get a blood draw warrant within minutes of a refusal.5National Highway Traffic Safety Administration. No Refusal Program If an officer says a warrant is being sought, it almost certainly is. Refusing during a no-refusal event usually delays the draw rather than preventing it, and you still face the administrative suspension for the refusal.
Can the Officer Search Your Car?
An officer needs either your consent or probable cause to search your vehicle. Under the automobile exception to the Fourth Amendment, probable cause to believe the car contains contraband or evidence of a crime does not require a warrant. Visible drug paraphernalia, an admission that drugs are in the car, or open containers in plain view can establish that probable cause.
The smell of marijuana is shifting legal ground. In states where marijuana remains fully illegal, its odor still provides probable cause for a search. In states with legal recreational or medical marijuana, courts are increasingly ruling that the smell alone, without other signs of illegal activity or impairment, does not justify a warrantless search. If an officer asks to search your vehicle, you can say no. If the officer searches anyway, the legality of that search is something your attorney can challenge later. Do not physically resist a search, even one you believe is unlawful.
The BAC Numbers the Officer Is Measuring Against
Every state treats a blood alcohol concentration of 0.08% as the legal limit for adult drivers.6Office of the Law Revision Counsel. 23 USC 163 – Safety Incentives to Prevent Operation of Motor Vehicles by Intoxicated Persons You do not have to feel drunk or look impaired to be over it. Two or three drinks in an hour can push many people past 0.08%, depending on body weight and other factors.
Two groups face much lower thresholds. Drivers under 21 are subject to zero-tolerance laws in every state, setting the maximum BAC at 0.02% or lower.7National Highway Traffic Safety Administration. Zero-Tolerance Law Enforcement Commercial driver’s license holders face a 0.04% limit while operating a commercial vehicle, and a single violation brings a one-year CDL disqualification; a second means lifetime disqualification.8eCFR. 49 CFR 383.51 – Disqualification of Drivers For a CDL holder, a DUI stop is a career issue as much as a legal one.
What Happens Next: Two Separate Cases
A DUI arrest launches two proceedings on different tracks: an administrative case about your license and a criminal case about the charge. Many people focus on the criminal side and lose their license by default because they missed the administrative deadline.
The Administrative Track
After arrest, the motor vehicle department moves to suspend your license based on the test results or your refusal. You have a limited window to request an administrative hearing, often as short as 7 to 10 days from arrest, depending on your state. Miss that deadline and the suspension takes effect automatically with no chance to fight it. The hearing is narrow: whether the officer had a lawful reason to believe you were impaired, whether the arrest was lawful, and whether the test evidence supports the suspension. The standard of proof is lower than in criminal court, and drivers often lose administrative hearings even when their criminal cases are later dismissed or reduced.
The Criminal Track
On the criminal side, you will be booked at the station, and a judge will set bail or release you on your own recognizance. If you are held in custody, the prosecutor typically has a few business days to file formal charges. The arraignment is your first court appearance, where you hear the formal charges and enter a plea. If you do not have an attorney by then, request a public defender at arraignment.
First-time DUI convictions carry a mix of penalties that vary by state but commonly include fines ranging from several hundred to a few thousand dollars, possible jail time (some states mandate a minimum even on a first offense), probation, mandatory alcohol education, and community service. The administrative suspension and the criminal penalties can stack.
The Financial Aftermath
The court-imposed fine is rarely the most expensive part of a DUI. The fallout extends well beyond what the judge orders.
- Thirty-one states and the District of Columbia require even first-time offenders to install an ignition interlock device on every vehicle they drive. Most states mandate the device for at least six months to a year, with installation and monthly monitoring running roughly $70 to $150 per month.9National Conference of State Legislatures. State Ignition Interlock Laws
- Most states require an SR-22 certificate of financial responsibility after a DUI, proving you carry at least minimum auto insurance. The filing fee is small, but the premium itself typically doubles or triples for the three years most states require SR-22 coverage.
- License reinstatement fees generally run $100 to $500.
- Court dates, mandatory classes, any jail time, and the inability to drive to work during a suspension add up to lost income that often exceeds the direct costs.
Added together, a first-time DUI routinely costs $10,000 or more over the following few years. That figure catches people off guard more than any other number in the process, which is why the decisions you make in the first few minutes of the stop matter so much.