Broward County Criminal Defense Attorney William R. Moore

What Tips Off a Police Officer for DUI Arrests?

Tolerance for alcohol varies from person to person and is correlated with factors such as sex, weight, experience, and the frequency with which a person consumes alcohol. These factors explain why one person might just feel relaxed after three drinks and another would feel quite impaired. Broward DUI Lawyer William Moore finds that clients report feeling widely varied levels of intoxication, from absolutely none to inability to remember the events, at the time of their DUI arrests. Law enforcement officials are trained to identify intoxicated drivers by both their driving and their behavior during a traffic stop, but their evaluations are imperfect. Still, which factors do police officers and sheriff’s deputies use to evaluate a driver’s condition?

Many law enforcement agencies have a specific set of guidelines. The National Highway Traffic Safety Association has published a list of symptoms for law enforcement officers to use when identifying intoxicated drivers. The percentages next to each behavior indicate the statistical likelihood – according to the NHTSA – that the vehicle’s driver is intoxicated. The following table and percentages are from the NHTSA:

Turning with wide radius 65%
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 10mph 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%

The list gives a good idea of some factors police officers will notice and may attribute to drunkenness. Interestingly, there is only a 60 percent chance that a driver who appears drunk actually is, which is one reason why the testimony of a police officer that a defendant appeared intoxicated is far from conclusive. Making unusually wide turns is actually more likely to be symptomatic of intoxication than appearing to be intoxicated is. A police officer looking to determine if a DUI suspect is intoxicated will look for evidence of intoxication, such as red eyes, a flushed appearance, the smell of alcohol on the suspect, and other factors.


Fort Lauderdale DUI attorney William Moore provides outstanding DUI defense in Broward, Fort Lauderdale, and Fort Lauderdale-Dade Counties. If you have been charged with a DUI, contact Fort Lauderdale DUI Lawyer William R. Moore, P.A.
This article should be used for informational purposes only and should not be construed as legal advice nor as implied representation of any person.
Article contributed by Mallory Shipman Esq.