Field sobriety tests in a drunk driving investigation

Of the three field sobriety tests approved by the National Highway Traffic Safety Administration, none are 100-percent accurate.

Most New York residents probably know that the state's laws on driving while impaired are incredibly strong. While a blood alcohol content of 0.08 percent is the main threshold for determining the intoxication of most drivers, it is possible to be charged with a driving while ability impaired offense with a BAC of only 0.05 percent . In addition, the laws indicate that any sign of impairment may make a person vulnerable to such a charge.

While it is only chemical tests-blood tests, breath tests or urine tests-that can actually determine a BAC level, there are other tests used by law enforcement officers during a drunk driving investigation.

These tests, referred to as field sobriety tests, are used to provide enough evidence to support placing a person under arrest. Failing these tests can be pointed to as some evidence of impairment. Therefore, understanding them is important for anyone who drives in New York.

What is the one-leg stand test?

As explained by FieldSobrietyTests.org, the one-leg stand test is used to evaluate a person's ability to balance while also performing other acts. A driver is asked to lift one leg, keep both arms by their sides and count out loud until instructed to stop.

The use of arms to balance, placing of the lifted foot down even for a brief moment and inability to count properly can all contribute to a driver's failure of this test. On its own, this test is said to be 65-percent accurate. It has the lowest accuracy rating of all three of the field sobriety tests used.

What is the walk-and-turn test?

As the name implies, in this test a driver must walk in a straight line and turn around and walk back. While walking, a strict heel-to-toe alignment must be maintained. Again, the driver must count out loud for the exact nine paces to be taken in each direction. This test is said to have an accuracy rating of 68 percent.

What is the horizontal gaze nystagmus test?

The eyeball has a natural jerking motion called a nystagmus that can be exaggerated after a person has consumed alcohol. In this test a driver must follow the motion of an object without moving their head and only by moving their eyes. The officer then notes when the nystagmus is noted as the eyeball moves from side to side. This test is 77-percent accurate.

What should a person do after being arrested for drunk driving?

The severity of the penalties for even a first-time DWI or DWAI offense along with the inaccuracy of field sobriety tests makes it important for any arrested driver to talk to an attorney. Getting the help of someone who knows what details to look for can be important when facing this situation.