Slow Reaction and Coordination

• Drinking alcohol slows your reaction time by 15 to 25 percent, according to the University of Texas at San Antonio. This affects your ability to quickly react to unexpected occurrences such as cars approaching, traffic lights and people crossing the road. Likewise, alcohol can affect your coordination. This can result in an inability to maneuver your vehicle or do more than one thing at once while driving. You may even become drowsy and close your eyes.
  
  

Poor Judgment and Perception

• Alcohol can affect your judgment and perception when it comes to gauging possible dangers on the road. You may not realize how fast another car is approaching or how close an item is on the road. You may also misjudge your own speed and drive too fast or too slow. This can cause you to speed, run lights, pull out in front of approaching cars and approach items and people on the road too closely.
  
  

Impaired Vision

• Alcohol consumption can affect your ability to see. You may experience blurred vision, and your eyes may focus on the same object for an extended period. As a result, you may focus only on the road and objects directly in front of you and neglect traffic on the sides and behind you. This can cause you to fail to respond to cars or people approaching on your sides or rear. Additionally, alcohol causes the pupils to dilate, which results in sensitivity to light.
  
  

False Confidence

• Consuming alcohol can make you feel invincible, causing you to take risks that you normally would not. You may feel more confident in your ability to drive when in reality you do not possess even your normal driving skill. You become more likely to participate in risky behaviors such as speeding, running lights and stop signs, pulling out in front of approaching cars and maneuvering between cars.
  
  

Poor Hearing

• Alcohol reduces your ability to hear clearly. Sounds may seem distorted or muffled and you may struggle to determine the direction from which sounds came. This can result in failure to hear warning bells and car horns.