Getting pulled over is stressful. When an officer suspects you’re impaired, that stress multiplies. Understanding what law enforcement actually looks for during a traffic stop helps you know what to expect and how these observations might later be used against you in court.
Our friends at Eastside DUI discuss how officers receive training to document specific behaviors and physical signs during stops. A DWI lawyer can review every detail of your stop and challenge observations that don’t hold up under scrutiny.
Driving Patterns Before The Stop
Police start building their case before they even flip on those lights. Certain driving behaviors catch their attention and justify them to pull you over. Watch for these common patterns:
- Weaving within your lane or crossing lane markers
- Driving well below the speed limit without an obvious reason
- Making unusually wide turns or cutting corners too tightly
- Stopping inconsistently at traffic signals
- Delayed reactions to changing traffic conditions
- Forgetting to turn on the headlights after dark
The National Highway Traffic Safety Administration has assigned different probability ratings to specific driving cues that might indicate impairment. But these behaviors alone don’t prove you’re intoxicated. Plenty of factors can cause similar driving patterns.
Physical Appearance And Behavior
Once you’re stopped, officers shift their focus to your physical condition and how you’re acting. They’ve been trained to spot signs that might suggest impairment. Bloodshot eyes? They’re noting it. Watery eyes, slurred speech, the smell of alcohol? All of it goes in the report. Officers watch how you retrieve your license and registration. If you fumble through your wallet or can’t quickly locate documents, they’re writing that down too. How you respond to questions matters. They listen for confusion, delayed answers, or statements that contradict each other. They’re watching whether you seem disoriented or struggle with simple instructions.
Field Sobriety Tests
Suspect impairment, and you’ll probably be asked to perform standardized field sobriety tests. These supposedly measure your balance, coordination, and ability to follow directions. The three standardized tests are the horizontal gaze nystagmus (where they track your eye movements), walk-and-turn, and one-leg stand. Officers score these based on specific clues they’ve been trained to identify. Here’s the problem. Field sobriety tests are incredibly subjective. Medical conditions affect performance. So do injuries, fatigue, nervousness, and even the shoes you’re wearing. Officers sometimes administer these tests incorrectly. Sometimes they score them wrong. Either way, the results can be challenged.
Chemical Testing Requests
After field sobriety tests, officers typically want a breath or blood sample. How they ask and what they tell you about refusing varies depending on where you are. Many states have implied consent laws. Your driver’s license comes with an automatic agreement to submit to chemical testing. Refuse, and you might face immediate license suspension. That refusal can also be used against you in court. Officers must follow specific protocols when they administer these tests. Breath test machines need regular calibration and maintenance. Blood draws must be performed by qualified personnel under sterile conditions. Mistakes in procedure can invalidate results completely.
Your Rights During The Stop
You do have constitutional protections. You’re required to provide your license, registration, and proof of insurance. That’s it. Beyond those basics, you can politely decline to answer questions about where you’ve been or whether you’ve been drinking. Field sobriety tests? You can refuse them, though refusing may lead directly to arrest. Chemical testing is trickier because of those potential administrative penalties. Remember this: anything you say becomes evidence. Officers often ask innocent-sounding questions specifically designed to gather incriminating information. Stay calm, be respectful, but limit what you volunteer. It protects you.
Building Your Defense
Police reports don’t always capture the full story. Officers make mistakes in their observations. They mess up testing procedures. Their documentation sometimes contains errors. Dashcam or body camera footage occasionally contradicts what’s written in reports. Medical records can explain what officers interpreted as impairment. Witness statements provide different perspectives. Maintenance logs for testing equipment sometimes reveal calibration problems. Every detail of your specific stop matters tremendously. If you’ve been arrested after a traffic stop, talk to an attorney who understands how these cases actually work. The observations and procedures used during your stop may contain weaknesses that significantly strengthen your defense.