The National Highway Traffic Safety Administration (NHTSA) has published a list of 24 visual "Cues" or indicators of drivers impaired by drugs or alcohol based on three field studies involving twelve thousand vehicle stops. Reproduced below are the 24 NHTSA cues, broken into four categories:
1) Difficulty Maintaining Proper Lane Position; 2) Speed and Braking Problems; 3) Vigilance Problems; and 4) Judgment Problems.
NHTSA's 24 Visual Cues Of Impaired Driving:
The NHTSA publication upon which this article is based is available for free download at: Visual Detection of DWI Motorists
Tennessee law enforcement officers are trained to look for the above-listed 24 visual cues when looking for impaired drivers. If you were stopped for suspicion of DUI or DWI and the basis of your stop did not include one of the above, you may have a basis for challenging the legality of your stop and any subsequent evidence police obtained from you, such as a blood or breath test. Challenging the legality of the stop is always the first step in fighting a DUI or DWI charge in Tennessee. Notice that speeding is not one of the 24 visual cues of impaired driving.