Reasons for DUI Stop


When a driver is pulled over for suspicion of DUI, there are some obvious symptoms of intoxication that an officer will look for or notice right away. Slurred speech, disorientation or confusion, bloodshot eyes and the smell of alcohol are each reasons for a police officer to have a closer look and ask the driver to step out of the vehicle for a field sobriety test.

The Less Obvious Signs of DUI

However, according to the National Highway Transportation Safety Administration (NHTSA), there are certain driving patterns that may alert police officers of potential drunk drivers as well. While some may be obvious, some may not be as apparent to people who are not in law enforcement.

The NHTSA has put together a list of the most common symptoms that a police officer may see out on the road that could indicate that a person is driving under the influence.

For each driving symptom, the NHTSA has assigned a percentage, indicating the probability that the driver exhibiting this symptom is driving while impaired. When an officer notices multiple symptoms from a driver, the NHTSA instructs them to add a ten percent likelihood of intoxication to the highest ranked symptom.

Symptoms of an Impaired Driver

Here are the list of suspect driving symptoms, ranked by the NHTSA in order of the most likely driving habits exhibited by drivers who are intoxicated:

Percent Chance of Intoxication Driving Symptom
65 percent chance of intoxication
  • Making a turn with a wide radius
  • Straddling center or lane marker
60 percent chance of intoxication
  • Appearing to be drunk (The NHTSA does not indicate exactly what this means)
  • Almost striking an object or vehicle
  • Weaving
55 percent chance of intoxication
  • Driving outside the designated roadway
  • Swerving
50 percent chance of intoxication
  • Driving more than 10 mph below the posted speed limit
  • Stopping in traffic for no reason
  • Drifting
45 percent chance of intoxication
  • Following too closely / tailgating
  • Driving with tires on center or lane marker
  • Erratic braking
  • Driving into oncoming traffic
40 percent chance of intoxication
  • Signaling inconsistently with driving actions
35 percent chance of intoxication
  • Slow response to traffic signals
  • Stopping inappropriately (not in traffic)
  • Making abrupt or illegal turns
30 percent chance of intoxication
  • Sudden acceleration or deceleration
  • Driving with no headlights after dark

According to the NHTSA, these are the most common driving symptoms seen in drivers who are intoxicated. Police officers are trained to look for signs of intoxication in each driver they encounter, but when they see a driver doing one or more of the above things out on the road, a traffic stop may be likely.

If you've been charged with DUI, speak to a local DUI lawyer as soon as possible. Fill out our free DUI case evaluation form or call 877-349-1311, and we'll help you get in contact with a DUI attorney in your area as soon as possible.

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