Most DUI arrests start one of two ways: either there’s a car accident, or police pull you over on “suspicion” of drunk driving. But what makes them suspect drunk driving in the first place? Are there certain signs they watch for, or does any unusual behavior count?
The answer is that police look for specific signs, and they have to follow rules around who they can pull over and why. We’ll look in detail at those rules and the types of driving that makes them suspicious.
Signs of Intoxicated Driving
Police don’t have a right to stop just any vehicle on the road. They need a reason to pull you over, and when it comes to guessing that you might be intoxicated, that reason gets fuzzy. That’s why the National Highway Traffic Safety Administration (NHTSA) put together a list of specific “cues” indicating a driver might be drunk. All the cues can be observed visually simply by watching a car from a distance.
These cues are not arbitrary. They came from officers across the country, and correlate with actual DUI cases. In other words, officers were asked what type of driving they observed from people who were later shown to be intoxicated by a blood or breath test. The officers gave an extensive list, which the NHTSA condensed down to just 24 cues.
Those 24 cues fall in four broad categories:
Problems Maintaining Proper Lane Position
- Crossing lane lines
- “Straddling” a lane line
- Turning too wide
- Nearly hitting a vehicle or object
Speed and Braking Problems
- Any difficulty stopping—such as stopping too soon, waiting too long to stop, or stopping in a jerky manner
- Accelerating or decelerating for no reason
- Varying speed
- Driving too slow (10 or more miles under the speed limit)
- Driving in the oncoming lane or going the wrong way on a one way
- Slow to respond to traffic signals (sitting at a green light)
- Slow to respond to an officer’s signals
- Stopping in the lane for no apparent reason
- No headlights at night
- Failure to use a turn signal, or using it in a way that does not match actual turns/lane changes
- Following too closely
- Improper or unsafe lane changes
- Illegal or improper turn (such as turning too fast)
- Driving off the roadway
- Stopping inappropriately in response to an officer (such as swerving off the road when the siren comes on)
- Inappropriate or unusual behavior in the car (such as arguing or throwing things)
- Appearing to be impaired
As you can see, some of these cues are very general. Many are things you could do sober as well. Officers are taught that if they observe two or more of them, the driver is potentially drunk.
Legal and Illegal Stops
Police are only supposed to pull you over if they have “reasonable suspicion” that you have committed a crime. The 24 cues are supposed to give them a way to determine reasonable suspicion for DUI. But they have ways around this. For example:
- “Swerving” is a very vague term. Officers can say they saw you swerving and give this as a reason for pulling you over.
- Once they’ve pulled you over, officers will usually ask, “Do you know why I pulled you over tonight?” They do this so you can give them a reason. If you admit you just rolled through a stop sign, they now have a valid reason for stopping you, even if they didn’t see it happen. The best answer is just, “No, officer. What seems to be the problem?”
- If you broke any other law while driving, such as speeding, officers have a valid reason to stop you. They may not even suspect you were intoxicated until after they pull you over and talk to you.
Officers are almost always able to find a reason to stop a driver. In many cases, saying they saw you “swerve” is their word against yours. In some cases, however, there may exist video evidence that differs from what an officer says. This can include traffic light cameras or even the dash cams of the patrol cars themselves. You may not know this video evidence exists, but a DUI lawyer can find out whether officers had a camera going and subpoena the footage. If their account doesn’t match the footage, this is one way a DUI lawyer can move to have your case thrown out. If there was no legal reason to stop you in the first place, then your rights were violated.
If you’ve been arrested for DUI, you deserve the best defense possible—and that means getting a good DUI lawyer. We have screened top Los Angeles DUI lawyers who offer FREE consultations, and are happy to match you with one. Fill out the form to the right and get your free consultation today.