Driving Manifestations

DUI Driving Manifestations

Now let’s talk about how officers and prosecutors try to detect and prosecute impaired drivers. Police officers are trained to look for certain signs when they are detecting potentially impaired drivers. The National Highway Traffic Safety Administration (NHTSA) published a list of signals to look for when detecting impaired drivers. These are known as DUI driving manifestations. Following is list of DUI driving manifestations, along with the probability that a driver committing each offense is intoxicated.

Turning with wide radius over 50%
Straddling center or lane marker 65%
Appearing to be drunk 60%
Almost striking object or vehicle 60%
Weaving 60%
Driving on other than designated roadway 55%
Swerving 55%
Slow speed (more than 10 mph below limit) 50%
Stopping (without cause) in traffic lane 50%
Drifting 50%
Following too closely 45%
Tires on center or land marker 45%
Braking erratically 45%
Driving into opposing or crossing traffic 45%
Signaling inconsistent with driving actions 40%
Stopping inappropriately (other than in lane) 35%
Turning abruptly or illegally 35%
Accelerating or decelerating rapidly 30%
Headlights off 30%


Speeding is missing from the list, even though it is a major reason for many DUI stops, because it requires more reaction time, braking distance, and physical control than driving a car at a regular speed—all of which are slowed by the presence of alcohol.

If your DUI arrest was the result of being stopped at a roadblock, then the arresting officer and prosecutor lack any impaired driving signs to use against you in court. This is a huge benefit to your case because the prosecution is now missing a major piece of evidence that they commonly rely on to secure convictions.

No matter why you were stopped for a DUI, it is important that you and your attorney understand how the underlying charges can affect the overall outcome of your case.