If police request a breath test in the United States, the request is usually related to a suspected impaired-driving investigation. The consequences of taking or refusing the test can vary significantly depending on the state, the type of test requested, and the circumstances of the traffic stop.
Breath-test requests often occur after officers observe signs of possible alcohol impairment.
What happens
During a traffic stop, an officer may:
- Ask questions about alcohol consumption
- Observe driving behavior and physical signs of impairment
- Conduct field sobriety tests in the United States before deciding whether additional testing is appropriate
- Request a breath test
Depending on the state and situation:
- The test may occur roadside using a portable device
- The test may occur later using evidentiary equipment at a police station or testing facility
Officers may continue the investigation regardless of whether a breath test is provided.
Additional evidence may include:
- Driving observations
- Statements made by the driver
- Video recordings
- Other physical evidence gathered during the stop
What determines the outcome
The outcome depends on:
- State law
- The type of breath test requested
- Whether the driver complies or refuses
- Other evidence available during the investigation
Some states impose administrative consequences for refusing certain chemical tests. These consequences may differ if you refuse a breath test under state implied-consent laws
In other situations:
- Refusal may become part of the evidence considered during later proceedings
The legal consequences of refusal are not identical across all jurisdictions.
What it may lead to
Common outcome:
- Completion of the test and continuation of the traffic-stop investigation
Possible escalation:
- Arrest for suspected impaired driving, including situations where a DUI arrest occurs following the investigation
- Administrative license actions under state law
Worst realistic outcome:
- Criminal charges related to impaired driving, including situations where DUI charges are filed after review of the evidence
- License suspension or revocation proceedings
- Additional penalties if refusal consequences apply under state law
The breath test itself is usually only one part of the overall investigation.
Common escalation triggers
- Signs of intoxication observed by officers
- Erratic or unsafe driving behavior
- Traffic collisions involving suspected impairment
- Open containers or other evidence observed during the stop
What this depends on
Outcomes may vary based on:
- State implied-consent laws
- Local enforcement practices
- Available evidence beyond the breath test
- Prior driving or DUI-related history
Procedures and legal consequences differ substantially between states.
Who controls the process
Breath-test investigations are generally conducted by state and local law enforcement agencies.
Administrative licensing consequences are typically handled through state motor vehicle systems, while criminal charges are handled through the court system.
Last reviewed: May 2026
This page describes typical operational outcomes. Individual cases vary.