How Blood Alcohol Content (BAC) Levels Impact a Person’s Ability to Drive

National Center of Disease Control (CDC) weighs in on predictable effects based on BAC

A person’s BAC refers to the Blood Alcohol Content found in a person’s body. This can be measured through means of a DUI breath or Chemical Blood test. If a certain limit is exceeded, the motorist was found to be driving impaired due to alcohol they will be arrested for DUI charges.

Each state has adopted its own legal limit. In Arizona, the legal limit is 0.08%. Arizona is considered to have one of the motorist DUI laws in the country because it goes a step further. Arizona motorists may be arrested for DUI even if their BAC does not exceed 0.08%; and even if the motorist has not alcohol in their system.

Arizona DUI Laws

This is because under A.R.S. § 28-1381 person may be found guilty of Driving Under the Influence if they are found to be “Impaired to the slightest degree based on alcohol or drugs; while in actual physical control of a vehicle if they are driving impaired to the slightest degree due to alcohol or drugs. The standard of 008% would not apply for drugs, and would not apply if they had a BAC lower than 0.08% if they were drinking and found to be impaired to the slightest degree.

DUI Classifications

DUIs that are not repeat offenses, and have no aggravating factor may be charged as a Misdemeanor. Higher the BAC levels call for increased jail terms and penalties.  The Misdemeanor ranges for BAC from lowest to highest are: DUI – Impaired to the slightest degree; DUI 0.08%, Extreme DUI 0.15% and over; Super Extreme 0.20%.

Effects of BAC levels on a person’s driving

According to studies published by the National Center of Disease Control (CDC) the following effects are expected with certain BAC levels The are known to have the following typical or predictable effects on driving.

• 0.02% to 0.05%-Some judgment lost, relaxation, increase in body temperature, altered  mood; decrease in visual function; decreased ability to perform to tasks at one time; Reduced ability to respond defensively in an emergency while driving; reduction of alertness and inhibition
  • 0.05%to 0.08%. – Judgment impaired; small muscle control reduction; reduced coordination; difficulty steering; reduced response to driving emergency; decreased alertness and inhibition;

• 0.08% to 0.10% – Poor coordination, balance, speech, vision, driving reaction time and control of vehicle; impaired judgment, reasoning, ad memory; short term memory loss; Inability to control speed of vehicle; reduced mind processing for road signs and or traffic signals;

• 0.10% to 0.15% – Clear deterioration of reaction time and control; poor coordination; slow thinking; slurred speech; inability to maintain lane position or apply breaks when necessary; loss of judgment and reasoning skills; vomiting; inattention to driving; substantial impairment in ability to process information they hear or see; and significant loss of balance;