Symptoms for Detecting Drunk Drivers

The following list contains symptoms that are used by police officers to detect drunk drivers. The list contains the symptom, followed by a percentage representing the chance that the driver’s blood alcohol content (BAC) is over the legal limit.

• - 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%