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 55 given for “Weaving” means that chances are 55 out of 100 that a driver who weaves at night will have a BAC equal to or greater than 0.10. (print out the actual booklet - PDF Format)

(Take the automated tour - 3.5 minutes )

• 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