1. Horizontal Gaze Nystagmus (HGN) Test.
The HGN test is used to assess whether a driver is impaired due to alcohol or drugs, and involves the ability of the eyes to track a moving object horizontally. The officer will stand approximately 12 inches away from the person's face and ask them to follow an object with their eyes. The officer will look for three distinct clues of impairment: lack of smooth pursuit, distinct and sustained nystagmus at maximum deviation, and the onset of nystagmus prior to 45 degrees.
The walk-and-turn test is designed to test a person's ability to divide their attention between physical and mental tasks. It involves walking heel to toe in a straight line while counting aloud in the correct sequence, then turning around correctly and repeating the process. Clues of impairment on this test include not being able to keep balance while listening to instructions, starting before instructions are finished, stopping during the test, not touching heel to toe or stepping off the line, using arms to balance, and turning improperly or incorrect numbers of steps.
3. One Leg Stand.
This test assesses a person's ability to perform a divided attention task while standing on one foot. The officer will ask the person to stand on one foot and count aloud in increments of thousands until instructed to stop. Clues for impairment include swaying, raising arms for balance, hopping, putting the foot down or not counting correctly.
4. Finger Counting Test.
The finger counting test is used to evaluate a person’s ability to concentrate and follow instructions while doing simple math problems. The test requires them to start with their thumb on their left hand and rapidly touch each finger as they repeat the numbers “one, two, three”. They must then reverse the order and do it again in the opposite direction. Impairment clues include mistakes in the counting sequence or losing count of the numbers.
5. Romberg Balance Test.
The Romberg balance test is an evaluation of a person's ability to maintain equilibrium while standing still. The officer will ask them to stand with their feet together, eyes closed and heads tilted slightly back for 30 seconds without swaying or using their arms for balance. Impairment clues include body swaying, use of arms for balance and opening one’s eyes during the test.
6. Alphabet Test.
The alphabet test assesses a person's ability to concentrate and follow instructions. The officer will ask the person to recite a part of the alphabet such as “A-L” or “Q-Z” backward without any errors or pauses. Impairment clues include not being able to begin correctly, pausing for more than three seconds, repeating letters, mixing up orders or stopping before completing the task.
7. Finger-to-Nose Test.
The finger-to-nose test requires a person to stand with their feet together and tilt their head back while touching the tip of their nose with their index finger on each side of their face alternately. Clues of impairment may include missing the nose repeatedly, needing assistance in finding their own nose and having difficulty in following the directions.
8. Hand Pat Test.
This test assesses a person's ability to divide their attention between physical and mental tasks. The officer will ask them to pat one hand with the other counting aloud as they do so until instructed to stop, then reverse the process. Impairment clues include not being able to keep rhythm or coordination, stopping during the test, or doing more than asked for.