In Ohio, the concentration of alcohol in a person’s system which defines illegal impairment while operating a vehicle is precisely defined by statute. This threshold is expressed in terms of blood alcohol content (BAC) and breath alcohol content. For drivers aged 21 and over, a BAC of 0.08% or higher constitutes a violation. Equivalent thresholds also exist for alcohol concentrations found in urine or blood serum/plasma.
Establishing these limits is crucial for public safety. By setting a clear demarcation, the state aims to deter impaired driving, thereby reducing alcohol-related accidents, injuries, and fatalities. Historically, these laws have evolved, often becoming more stringent over time as scientific understanding of alcohol’s effects on driving ability has deepened and societal attitudes towards impaired driving have shifted.