How does blood alcohol concentration affect driving abilities?

Drivers must ensure that they’re in good condition to drive. One thing that they must avoid is impaired driving. Most drivers know that it’s illegal to drive with a blood alcohol concentration (BAC) of over .08% for drivers who can legally consume alcohol, but some may not understand why that number is important.

While .08% is legally drunk, impairment can begin at much lower levels. As BAC rises, so does the level of impairment, affecting cognitive, motor and sensory functions. These are a few of the basic impairments that occur when a person consumes alcohol.

Cognitive impairment

Cognitive impairment is one of the first effects of alcohol. Drivers may experience a visual decline and changes in their ability to multitask. Information processing and rational decision-making skills also decrease. This makes it difficult for drivers to determine how to react to situations that occur as they drive.

Motor skills degradation

Alcohol also has a significant impact on motor skills, which are essential for safe driving. Drivers may find their coordination and ability to track moving objects impaired. Reaction times slow down, making it harder to respond quickly to sudden changes on the road. At higher BAC levels, muscle control deteriorates, which can lead to poor steering, braking, and overall vehicle control.

Sensory perception reduction

Sensory perception is crucial for recognizing and reacting to one’s driving environment. Alcohol affects sensory functions at relatively low BAC levels. Drivers may experience a reduction in the ability to perceive distances accurately, which makes it difficult to judge the speed and position of other vehicles. Night vision and the ability to detect signals and signs also diminish.

All of these effects of BAC can lead to a motorist driving in an unsafe manner when they’re behind the wheel. Related actions, such as failing to stop at stop signs or drifting between lanes, can provide officers with reasonable suspicion to initiate a traffic stop. Once a driver is arrested for impaired driving, they must consider their defense strategy options to determine how best to proceed.