Final answer:
A driver is presumed to be Driving While Ability is Impaired (DWAI) with a BAC between 0.05% and 0.07%. Breathalyzer tests are used to determine a driver's BAC, and the legal BAC is 0.08% in most states.
Step-by-step explanation:
The driver with a BAC between 0.05% and 0.07% is presumed to be Driving While Ability is Impaired (DWAI). It's important to note that this range can vary slightly by state. A BAC above 0.08% is considered to be legally in almost all US states.
However, signs of alcohol intoxication can start to appear even after consuming only two alcoholic drinks, impacting tasks that require skill and judgment. Breathalyzer devices are used by law enforcement to measure a driver's BAC, which can result in charges if it's above the legal limit. The body metabolizes alcohol at a rate of approximately 0.015% BAC per hour.