Published on:

One Leg Stand (OLS):  A NHTSA Standardized Field Sobriety Test (SFST)

As you will recall, Susan Hartman, of the Law Offices of Susan L. Hartman, attended The National Highway Traffic Safety Administration (NHTSA) and The International Association of Chiefs of Police (ICAP) approved DWI Detection and Standardized Field Sobriety Testing Practitioner Course, as presented by Mr. Robert La Pier.

The course went through the three standardized field sobriety tests (SFST’s), as laid out by NHTSA:  1.) The horizontal gaze nystagmus, (HGN); 2.) The walk and turn, (WAT); and 3.) The one leg stand, (OLS).  These are the only tests that have been validated by NHTSA and should be used by law enforcement in evaluating each potential DUI.  It should be noted that these tests were only validated to correlate to a specific blood alcohol content (BAC) and they are not be used to show impairment.

The two previous blog articles discussed the HGN and WAT tests. This article will address the OLS test.

The NHTSA manual states that this “test requires a reasonably dry, hard, level, and non-slippery surface.”  If the person is wearing heels that are more than two inches, they should be given the choice to remove the shoes and perform the test barefooted.

There are many reasons why a person may not be able to adequately perform this test, regardless of their consumption of alcohol.  For instance, as a person ages, balance and coordination is more difficult.  If a subject has any current or prior injuries to their back or legs, they suffer from inner ear problems, or they are overweight by 50 or more pounds, they may have problems performing the test.  However, in my experience, officers often state, “I will take your concerns and medical issues into consideration,” and then they proceed with having the subject perform the test.

The OLS test is another divided attention test. It has two stages: 1.) The instructions stage for initial positioning and verbal instructions; and 2.) Demonstrations and instructions for the balance and counting stage.

During the initial positioning and verbal instructions, the cop should tell the subject to stand with their feet together, their arms by their sides, and to not start the test until told to begin.  The subject should then be asked, “Do you understand the instructions so far?”

Then for the second stage, the officer should explain and demonstrate the test as follows: When I tell you to begin, raise either leg approximately 6 inches off the ground, keep both legs straight, with your arms to your sides.   While holding this position, count out loud in the following manner, “one thousand one, one thousand two, one thousand three,” and so on until I tell you to stop.  Keep your arms at your sides and continue to watch your raised foot.  Do you understand?

The subject is then told to begin the test, as the officer times the test, stopping at 30 seconds.  If the person puts their foot down, they are to be instructed to pick their foot back up and continue.

There are a maximum of 4 clues in this test that the officer is looking for.  If the person sways, uses their arms to balance, hops, or puts their foot down, they are given one clue.  A slight tremor is not swaying and the arms must be 6 or more inches from the body to be counted as a clue.  Each is one clue regardless of how many times the clue is seen during the test.

If 2 or more clues are noted, or if the person is unable to perform the test, there is an 83% chance that the driver is at or above a .08 blood alcohol content.  This means that this test is 17% inaccurate!  An earlier NHTSA study reported the OLS to be 65% accurate and 35% inaccurate in determining if a person is at or above a .10 BAC.  To my knowledge, NHTSA has never addressed the discrepancy of the results of these studies.

When an officer testifies, it often becomes apparent they did not follow NHTSA’s standardized procedures for conducting the test and evaluating the results.  For example, I have seen cops count the same clue several times.  For instance, subject puts their foot down twice, and the officer counts that as 2 clues. This is wrong!  The officer should note only one clue observed no matter how many times the same clue is seen in the test.  If the cop did not administer or score the test properly, the test results will be inaccurate and your case can be impacted in your favor.

If you have been charged with drunk driving in San Diego County, you owe it to yourself to hire a DUI defense attorney who knows how to properly administer and evaluate the SFST’s and how the officers should be conducting themselves in the field when doing a DUI investigation.  Contact the Law Offices of Susan L. Hartman today for your free phone consultation: (619) 260-1122.