The Science Behind Drunk Driving

The Science Behind


If you take a sip of alcohol, you should not be driving.  NHTSA reports that 32% of fatal car crashes involve alcohol. Across all 50 states, it is illegal to be driving with a Blood Alcohol Level (BAC) of 0.08. Many states have adopted a zero-tolerance policy – if a person has any alcohol in their system, it is a crime.  But what actually happens when you drink alcohol and decide to get behind the wheel?

What happens when you consume alcohol?

Alcohol is a depressant.  It slows down the function of the central nervous system.  It negatively affects a person’s cognitive and motor skills.  These are the skills that a necessary for safe driving such as judgement, coordination, vision, reaction time, concentration, and comprehension.  Alcohol is absorbed into the blood.  The more a person consumes, the greater the amount of absorption.

The factors that affect BAC

There are many factors that can affect a person’s Blood Alcohol Concentratin (BAC).  Even if two people, of the same size and build, drink the same amount of alcohol, they can have varying BAC levels.  Some of these factors include:

  • The amount of alcohol consumed
  • The time period when alcohol is consumed
  • Body weight
  • Amount of food consumed
  • Sex
  • Age
  • Physical fitness
  • Family History
  • Drug Usage
  • Where the alcohol is consumed


What happens at each BAC level?

Even before getting to the BAC limit of 0.08, there are clear effects that alcohol has on the body.  This table outlines the typical effects of alcohol and how they affect a person’s diving ability (information sourced from MADD and the CDC):

BAC (1)

DUIs and Insurance

Drunk driving is incredibly dangerous.  If a person gets behind the wheel while intoxicated, there can be tremendous consequences  If caught and conviceted, a person may be charged with a DUI .  A DUI comes with many legal implications, but it can also affect auto insurance policies.  Since the cost of insurance will vary case to case, a DUI will increase the amopunt a person pays for their auto insurance.  Insurance agencies may deem a person to be high-risk.  After a DUI a person’s premium could increase by hundreds of dollars.  Over time, a person with a DUI could be spending thousands of dollars extra on insurance.

For any questions about drunk driving and insurance, you can speak to an Encharter agent by calling 888.754.8299.

If you are ever caught in a situation where you have been drinking, do not get behind the wheel of a car.  There are always alternative options including calling a friend, calling a taxi, or using a ride share service such as Uber.  Remember: buzzed driving is drunk driving.


Science NetLinks: Alcohol
NCADD: Driving While Impaired
Esurance: The Science of Drunk Driving
Total DUI: Scientific Effects of Drunk Driving
Progressive: How Does a DUI Affect your Insurance Rate?
MADD: Understanding .08
CDC: Effects of Blood Alcohol Concentration

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