NHTSA Standardized Field Sobriety Testing (SFST) Overview

There are three (3) field sobriety tests that make up the National Highway Traffic Safety Administration (NHTSA) Standardized Field Sobriety Test (SFST) battery:

1. The Horizontal Gaze Nystagmus (HGN) Test;
2. The Walk-and-Turn (WAT) Test; and
3. The One-Leg-Stand Test.

“If any one of the standardized field sobriety test elements is changed, the validity is compromised.”

NHSTA, Student Manual: DWI Detection and Standardized Field Sobriety Testing


In Missouri, officers are trained to follow the Standardized Field Sobriety Testing (SFST) procedure of the National Highway Safety Administration (NHTSA). The three (3) tests set out in the NHTSA SFST procedure are made part of Missouri’s uniform Alcohol Influence Report (AIR), which is completed by officers when they arrest a person for driving while intoxicated (DWI) in Missouri.

This page is intended to be a resource for attorneys and non-attorneys interested in learning more about the detailed SFST procedures set forth by the NHSTA.