Final answer:
The risk of causing a motor vehicle accident increases when a motorist's BAC is slightly above .05 percent, due to the impairing effects of alcohol on driving abilities such as coordination, judgment, and reaction time. A BAC above the legal limit of 0.08% BAC in U.S. states further heightens this risk, and only time can effectively lower BAC after drinking.
Step-by-step explanation:
If a motorist has reached a BAC of slightly above .05 percent after drinking, the risk for causing a motor vehicle accident increases significantly. Alcohol impairs many of the skills that are required for safe driving, such as coordination, judgment, and reaction time.
At this level of intoxication, some observable effects include lack of coordination, blurred vision, and a noticeable reduction in reaction times. Due to these impairments, the likelihood of a traffic accident occurring is heightened.
Although the legal limit for intoxication in most U.S. states is 0.08% BAC, individuals can show signs of impairment and increased accident risk at lower levels.
Therefore, even a BAC of just above 0.05% may be sufficient to compromise driving abilities and raise the risk of an accident occurring. This risk is exacerbated as the BAC level climbs closer to or surpasses the legal limit.
The metabolism of alcohol by the human body, which occurs at an average rate of 15 mg/dL per hour, means that it is crucial to give the liver enough time to break down alcohol before driving. Strategies such as drinking coffee or taking a shower are ineffective in speeding up this process, and only the passage of time can ensure the reduction of BAC to safe levels.