Guide for Detecting Drunk Drivers at Night

The below explains the visual cues contained in the DWI Detection Guide provide by the U.S. Department of Transportation. The number given after each visual cue is the probability that a driver exhibiting that cue has a BAC equal or greater than 0.10. For example the 65 for the first cue, Turning With Wide Radius, means that chances are 65 out of 100 that a driver who turns with a wide radius at night will have a BAC equal to or greater that 0.10. (print out the actual booklet - PDF Format)

Turning With Wide Radius Straddling Center or Lane Marker Appearing to be Drunk Almost Striking Object or Vehicle Weaving Driving on Other Than Designated Roadway Swerving Speed Slower Than 10 M.P.H. Below Limit Stopping Without Cause in Traffic Lane Following Too Closely

Drifting Tires on Center or Lane Marker Braking Erratically Driving Into Opposing Crossing Traffic Signaling Inconsistently With Driving Actions Slow Response to Traffic Signals Stopping Inappropriately (Other Than in Traffic Lane) Turning Abruptly or Illegally Accelerating or Decelerating Rapidly Headlights Off

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this page originally posted 12/20/98 updated to tour format, 1/28/99, then to Squarespace for the last update 6/4/2009 since 1997