What is a key indicator used in field sobriety tests?

In field sobriety tests, a key indicator of impairment is the driver's ability to follow instructions and maintain balance. These tests are specifically designed to assess both physical coordination and cognitive functioning under the influence of alcohol or drugs.

When a driver is asked to perform tasks such as walking in a straight line, standing on one leg, or following verbal instructions, the evaluation focuses on how well they execute these tasks. Impairment often results in a lack of balance, inability to follow multi-step directions, and difficulty in motor coordination. Therefore, these abilities serve as critical indicators of a driver’s sobriety during the assessment process.

While other factors like the vehicle's condition, the time taken to complete the test, and the odor of alcohol can provide context or additional signs of intoxication, they are not the primary indicators used within the structured environment of the field sobriety test itself. The emphasis is on observable behaviors during the tests to provide law enforcement officers with a more objective basis for determining a driver's impairment.