What 3 Tests Are Commonly Used for Field Sobriety Tests?

December 3, 2014

There’s No Substitution For Experience

By Brian D. Roman, Attorney at Law

It is likely that most Massachusetts drivers have heard of field sobriety tests; however, they may not know what the most common tests are. The Standardized Field Sobriety Test is comprised of three main tests that are used by authorities to look for impairment: the horizontal gaze nystagmus test, or HGN test, the one-leg test, and the walk-and-turn test.

When a police officer uses the HGN test, they are looking for nystagmus, or involuntary jerking, of the eye, at a horizontal level. The officer may conduct this test by slowly moving a pen or a flashlight horizontally in front of the eyes while instructing the person to follow the object without moving their head. In the one-leg test, the person must stand on one foot with the second foot held 6 inches above the ground. They must then count in thousands for thirty seconds. Finally, in the walk-and-turn test, the person must take exactly nine steps, heel-to-toe. Then, they must turn on one foot and continue back the way they came.

In each test, officers may look for indicators of impairment, such as loss of balance, failure to follow instructions and failure to focus on objects. The tests have a certain degree of accuracy, with 77 percent of people who exhibit HGN found to have a BAC of .10 percent or higher. For the one-leg test and the walk-and-turn, 68 percent of people and 65 percent of people are found to have a BAC of .10 percent or higher, respectively.

While the field sobriety tests do provide indicators of impairment, not everyone can do the tests due to physical or mental impairments. If someone is taken into custody on suspicion of drunk driving, it is recommended that they seek advice from an attorney to potentially determine if the case can be challenged due to the field sobriety tests being improperly conducted.

Source: National Highway Traffic Safety Administration, “ The Highway Safety Desk Book “, November 30, 2014

Police car with flashing red and blue lights, night setting, blurred city lights in background.
October 21, 2025
Understanding Massachusetts Domestic Violence Laws: What You Need to Know Before You Speak to Police
Man in interrogation room being questioned by two people in red suit.
May 20, 2025
Being charged with a criminal offense can be overwhelming, but having a criminal defense attorney on your team can help you assess the charges against.
Lawyer in suit writing at desk, gavel and scales of justice present.
April 30, 2025
Being charged with assault and battery in Massachusetts can disrupt your life in ways you might not anticipate.
A book titled
April 22, 2025
Facing a domestic violence charges can feel overwhelming.
Judge's hands writing, gavel, and sign reading
March 6, 2025
Getting a child support order modified is not a given. Talk with a family lawyer right away for specific help with your case if you need a modification.
Sad boy with parents in background, sitting on sofa.
February 10, 2025
If you are involved in a child custody dispute, be aware of the rights that you have as a parent.
Hands of two people holding a toy house, symbolizing property division.
January 28, 2025
Here in Massachusetts, property is divided a bit differently in a divorce than it is in some states.
Gavel with wedding ring on table, couple signing documents, possibly a divorce settlement.
November 14, 2024
You can file for divorce in Rhode Island if you or your spouse has lived in the state for at least 12 months.
Statue of Lady Justice with scales and a gavel on a desk in a sunlit office.
March 6, 2024
In the realm of legal jurisprudence, one fundamental principle stands tall as a pillar of protection for individuals: the privilege against self-incrimination.
Handcuffs and gavel on a dark surface, suggesting a legal or justice context. Blue and red lighting.
October 4, 2023
In the complex realm of criminal law, defending individuals charged with drug possession requires a unique blend of expertise, empathy, and unwavering dedication.