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What do the police look for when patrolling for drunk drivers?

The police are trained to look for certain driving patterns that may signal the driver may be under the influence of alcohol or drugs. However, the police only have to witness the most minor traffic violation as a reason to make a traffic stop. It is during the traffic stop that the police may look for additional evidence that the driver may be impaired.

Police officers also know when and where drunk driving is more likely to occur, including days of the week, holidays, peak drunk driving hours, and near bars, restaurants, or sporting events. However, just because the police made an arrest for driving under the influence (DUI) in California does not mean the traffic stop was legal.

If the police made a traffic stop without a valid reason or violated your constitutional rights in making an arrest, you should contact the experienced East Bay DUI lawyer Lynn Gorelickto fight for justice and challenge the criminal charges against you.

Police Officers Setting Up in the Right Time and Place

Police officers know when and where drunk driving is more likely to occur. They can simply set up in a driveway, parking lot, or alleyway near those areas and wait to look for any driver who makes the slightest driving mistake.

There are obvious days when impaired driving tends to peak. This includes holidays like the 4th of July, Memorial Day, New Year's Eve, and the day before Thanksgiving (Drinksgiving). Not surprisingly, Fridays and Saturdays also have higher rates of DUI arrests. Finally, DUIs are more likely to occur near closing time or after last call, late night or in the early morning hours.

To justify a traffic stop, any driving violation could be enough to make the police turn on their lights and sirens. This could include anything from illegal window tint, broken taillight, failing to turn on headlights at night, or expired registration. However, there are other signs that police look for when a car is driving that may indicate impairment.

Signs of a Driver Who May Be Impaired

Certain driving patterns may make a driver a target for a DUI traffic stop. Unfortunately, any inattentive driving can appear to some officers like the driver may be impaired even if the driver is totally sober. From the driving patterns, a driver who is texting, fishing for something in the glove box, or talking to passengers in the back may look like he or she could be impaired. Signs of impaired driving may include:

  • Sudden breaking,
  • Crossing over the median,
  • Driving too slow,
  • Sudden turns,
  • Weaving or swerving,
  • Failure to turn on the headlights, or
  • Delayed response to traffic signals.

Signs of Alcohol During the Traffic Stop

After the initial traffic stop, the police may be looking for any and every sign of unlawful activity, including impaired driving. This includes looking for visual clues, smell of alcohol or drugs, and talking with the driver to look for contradictions or changes in the driver's story.

Visual Signals:

  • Empty beer cans on the floor
  • Bottles of alcohol sticking out under the seat
  • Marijuana in the ashtray

Smell of Alcohol or Drugs:

  • Smell of marijuana
  • Alcohol on the breath
  • Inhalants
  • Excessive aerosols or body spray to cover alcohol or marijuana smells


  • Difference in where the driver says they were going and the driver's address
  • Driving to places that are closed
  • Driving in the wrong direction
  • Changing the number of drinks reported
  • Changes in the driver's story

In addition, there may be visual signals of impairment due to alcohol or drugs. Unfortunately, there may be a number of innocent reasons for having these signs, including being tired, allergies, or nervousness. Commonly cited signals of impairment may include:

  • Bloodshot eyes,
  • Slurred speech,
  • Stuttering or rambling speech, or
  • Delayed response.

Police Accusing the Driver of Being Drunk When the Driver is Sober

It can be frustrating for a driver who is pulled over for some unknown reason because the police immediately put the driver on the defensive. The questioning also makes the driver feel like he or she is guilty of doing something wrong, even if the driver is totally sober. When the police put the driver in the hot seat, the driver may feel anxiety and appear guilty even when the did nothing wrong. The police use this to their advantage and make not of any inconsistencies to justify an arrest.

If you are accused of driving drunk when you were fine to drive, there are defenses available to challenge your arrest and clear your name. East Bay attorney Lynn Gorelick has more than 30 years of DUI experience and understands how to challenge DUI charges. If you have any questions about your DUI or driving restrictions, contact East Bay DUI defense lawyer Lynn Gorelick today.

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