Traffic Stops: The Precursors of Most DUI Investigations & Arrests
The Most Common Types of Traffic Stops That Lead to a DUI Investigation in California
If you’ve been pulled over in California and arrested for DUI, you may be wondering why the officer stopped you in the first place. Many DUI cases begin with something seemingly minor — a simple traffic infraction that escalates into a full investigation. Understanding the most common reasons for DUI traffic stops can help you (and your attorney) identify potential defenses in your case.
Speeding and Other Moving Violations
One frequent reason for a DUI stop is speeding. Officers are trained to look for erratic driving patterns that might suggest impairment, such as:
Sudden acceleration or braking
Inconsistent speeds
Unsafe lane changes
A speeding ticket may seem straightforward, but once the officer approaches your window and notices the odor of alcohol or slurred speech, the encounter can quickly turn into a DUI investigation.
Weaving or Lane-Drifting
Officers often cite “weaving within a lane” or failing to maintain lane position as reasons for initiating a stop. Even subtle drifting can raise suspicion, especially late at night or near bars and restaurants. However, weaving alone does not always justify a DUI stop. Courts have ruled that slight lane deviations without other indicators of impairment may not provide enough cause. An experienced DUI defense lawyer can help determine whether the officer truly had reasonable suspicion to pull you over for weaving or lane-drifting.
Equipment Violations
Many DUI arrests begin with something as minor as:
A broken taillight or headlight
Expired registration
Tinted windows
Failure to display a front license plate
These stops are legal as long as the officer observes an actual violation. In most cases, it makes no difference what is motivating the officer to pull you over. Once the stop occurs, any signs of impairment — such as bloodshot eyes or the smell of alcohol — may lead the officer to conduct field sobriety tests or request a breath sample.
Traffic Signal or Stop Sign Violations
Running a red light, failing to make a complete stop, or rolling through a stop sign are other common precursors to a DUI stop. These infractions often occur at intersections monitored by patrol units, especially during weekend nights when DUI enforcement is high.
Accident or 911 Reports
Sometimes, a DUI investigation starts without a moving violation at all. Officers may respond to:
Traffic collisions, even minor fender-benders
Reports of erratic driving from other motorists
Vehicles stopped in traffic lanes or on the shoulder
In these situations, the officer’s initial contact is usually for safety or welfare reasons, but any signs of intoxication can quickly shift the focus to DUI enforcement.
Why the Reason for the Stop Matters
Under California law, an officer must have reasonable suspicion that a traffic law has been violated before pulling you over. If the stop itself was unlawful, your attorney can file a motion to suppress evidence — potentially resulting in exclusion of critical evidence necessary to prove the case against you.
Even a valid stop doesn’t guarantee a valid arrest. Field sobriety tests, breathalyzer results, and other evidence must also meet strict legal standards. An experienced DUI defense lawyer will scrutinize every step of the process to protect your rights and challenge the prosecution’s case.
Talk to a California DUI Defense Attorney
If you were arrested for DUI in California, don’t assume your case is open and shut. The circumstances of the traffic stop can make a major difference in the outcome. Our law office defends clients throughout Northern California who have been accused of driving under the influence. We’ll review the details of your stop, the officer’s conduct, and the evidence against you to build a strong defense.
Contact Davis W. Hewitt today for a confidential consultation. I hope you enjoyed reading this as much as I enjoyed writing it!
