It can be difficult for police officers to determine the difference between a drunk driver and someone who is simply a poor driver. Breathalyzers can determine intoxication more accurately, but police also have visual cues to spot drunk drivers to give themselves an idea of the driver’s intoxication level. Visual cues also help police officers identify people they should pull over. There are several tip-offs that a driver may be intoxicated, both while driving and after the driver is pulled over.
Reasonable Suspicion and Probable Cause
Legally, a police officer must have reasonable suspicion or probable cause to pull someone over. A driver must be doing something to give some indication of driving under the influence. If an officer pulls a driver over without reasonable suspicion or probable cause, even if the driver is intoxicated, it will affect the charges. It is called the “exclusionary rule.” The court must throw out any evidence that the police officer obtained after he or she illegally pulled over the driver. Courts will often dismiss charges or offer better plea bargains if the police officer did not have a reason to suspect intoxication.
Difficulty Staying in the Lane
One of the easiest ways that police officers can spot an intoxicated driver is if the driver is having a hard time staying in their own lane. Some of the most common instances of this include:
- Weaving through traffic and across lines
- Straddling the lane lines
- Drifting towards one side of the road
- Swerving
- Unreasonably wide turns
Difficulty With Speed and Braking
Intoxication can affect a driver’s ability to judge speeds and distances, and so many impaired drivers have a hard time following the speed limits on roads and braking correctly. The most common situations include:
- Stopping at an odd angle
- Stopping noticeably too close or too far from the correct spot
- Making jerky stops
- Sudden speed changes
- Difficulty staying at a consistent speed
- Driving 10 or more miles per hour above the limit
Even though speeding can be part of an officer’s suspicion, it is not enough by itself. Because many people speed when they are sober, police officers must have additional reasons to pull someone over. For example, an officer could pull a driver over if he or she was speeding as well as swerving in-between lanes.
Difficulty With Awareness
Alcohol consumption affects a driver’s awareness of conditions around them. Drivers impaired by alcohol cannot pay attention as well as drivers who are not impaired. Some common circumstances of unaware driving include:
- Driving in the wrong direction
- Responding slowly to traffic signals
- Stopping or slowing down quickly for no reason
- Using the wrong turn signal
- Driving without headlights in the dark
Poor Judgement
Along with poor awareness, impaired drivers usually have difficulty with judgment. After extensive alcohol consumption, making reasonable decisions becomes more difficult. Impaired drivers also tend to take risks they would not in other circumstances. Some risky behaviors that can indicate poor judgment include:
- Tailgating
- Making illegal turns or driving in the wrong lane
- Unsafe lane changes
- Driving off the road
Indicators After Someone Has Been Pulled Over
Once a police officer has decided to pull someone over, he or she needs to look for other visual cues once the driver gets out of the car. It is usually easier to tell how intoxicated someone is based off of personal interaction. Some of the things police officers look for after a driver is pulled over include:
- The smell of alcohol
- Open containers in the car
- Slurred speech
- Slow responses to questions
- Poor motor skills
- Difficulty supporting him or herself
- Bloodshot eyes