• Topics Covered in This Section
  • Horizontal Gaze Nystagmus (HGN)
  • Vertical Gaze Nystagmus
  • Walk And Turn
  • One Leg Stand (OLS)

The formal name of the roadside tests is Standardized Field Sobriety Tests (SFSTs). The important thing to know first and foremost is that as stated in the title, they are Standardized; Administered the same way each and every time by every officer or qualified administrator, upon every subject. If you are an officer in New York, Miami, Los Angles. Seattle or Alaska, if you are SFST NHTSA qualified, you do them the same way, ALWAYS.

Washington law enforcement officers are all trained under the National Highway Traffic Safety Administration (NHTSA) and International Association of Chiefs Of Police (ICAP) guidelines for these tests. Knowledge of the NHTSA standards is imperative to any Washington DUI Defense due to the fact that these tests are relied upon as proof in DUI trials. In some cases they are the only alleged “evidence” of the accused driver being DUI.

There are 3 tests that are the Official field Tests under NHTSA guidelines and everyone who trains to learn these tests is issued a manual for the course which is 24 hours long and should include a “wet lab” to tests the students skills learned and practiced in class. The Washington State Patrol (WSP) has various years of NHTSA training manuals available. While simply reading the manual is helpful, a student requires the actual course with qualified Instructors, exams, and graded practice sessions to become qualified to administer the tests. The 3 Standardized Tests are: HGN, Walk and Turn, and the One Leg Stand.

Horizontal Gaze Nystagmus (HGN)

The first of the 3 tests is the HGN. It is a test designed to determine whether a person has consumed alcohol. It is not a test that is admissible in Washington for any use but for that. Horizontal means that there is a imaginary line the stimulus moves back and forth on, Gaze indicates use of the eyes, and Nystagmus is what the officer is looking for, a slight and subtle jerking or twitching of the eyeball as it moves to the left and right. Most officers will describe this as a marble rolling over glass that encounters sand, or sometimes as windshield wipers on a dry windscreen. Most use this description due to the fact it is a description contained in the manual. Nystagmus does not affect a person’s vision. In fact, some people have naturally occurring Nystagmus and they can see just fine.

The test is structured and requires a person to follow a stimulus, usually a pen or a fingertip with their eyes only. While it is not a vision test, the subject does need to be able to see and glasses are to be removed as is headway, to ensure that the eyes are seen clearly.
The test is divided into two parts: the first part is what I like to call Medical Checks, which is done to make sure the person is a suitable subject for the test and remind them, or initially tell them that this is a voluntary test. The officer will place a subject in a position where they stand with their hands at their sides, feet together and to stay that way while the test is conducted.

The officer then confirms that the person can see the stimulus and positions it in front of the person at a distance of 12 – 15 inches from their face just above the bridge of the nose. Once the person confirms they can see the officer will look to see that the person has Equal Pupils, no resting Nystagmus, and then begins to move the stimulus to the subjects left, always left, to determine that their eyes track equally as the stimulus begins to move side to side. There is no set number of passes to ensure equal tracking, but the standards suggest 2 passes. If the person has resting Nystagmus, unequal pupils, or does not track with both eyes equally the test should not be done.

The actual test is the next phase after the officer determines that the person is a suitable candidate. The officer first checks for the clue of “Lack Of Smooth Pursuit” (LSP). Always staring with the subjects Left eye the officer moves the stimulus slowly, about 2 seconds, out to as far as the eye can go and then returns back to center and then makes the right eye follow in the same way. The officer returns the stimulus to center and then repeats the pass with the left eye for second time, back to center and repeats with the right eye. There is ALWAYS 2 passes per eye. During this time the officer is looking for that slight twitch or hiccup of the eyeball as it moves on a horizontal plane.

The next phase of the test is the same movement from center, beginning with the LEFT eye again officer begins looking for the second clue of “Distinct And Sustained Nystagmus” (Distinct) at maximum deviation. This requires the same movement of the stimulus but when the eyeball gets to as far left and right as it can and then the officer holds the eye at its maximum point for a count of at least 4 seconds. At this eye endpoint everyone will exhibit Nystagmus, but only briefly. Those who have consumed alcohol will have “sustained” nystagmus and therefore clue is not counted until it is sustained for at least 4 seconds. The stimulus is then returned to center and then the right eye is checked for this clue. The pass is then repeated for both eyes. Always 2 passes for each eye.

The last clue the officer looks for is “Onset Prior To 45 Degrees” (Onset). The officer is looking for the point where the eyeball begins to show Nystagmus and if see prior to 45 degrees (center being a straight line out from the bridge of the nose, and 90 degrees being the person shoulder, 45 degrees is estimated somewhere in between). For this clue the officer MUST slow the pace of the stimulus down from the 2 second pace of the prior clues, to that of about 4 seconds. While 4 seconds is a good suggested stimulus speed, in reality it should be as slow as necessary to clearly see Nystagmus as the stimulus goes from center towards the shoulder of the subject. The point at which the officer sees, or thinks he see the eyes twitch (Nystagmus) he is required to stop the stimulus movement and verify that it was actually seen. Of the eye discontinues to twitch the officer must continue the slow movement outward until Nystagmus is actual seen and verified by pausing. The officer is not required to state at what point the Nystagmus is seen, but rather simply guesstimate if it prior to 45 degrees. Seeing Nystagmus prior to 45 degrees is the actual clue, and there is no “magic degree point, only that it be seen “prior to.” Once again, this final stage is to be done in both eyes two times.

There are 3 clues as described above, but there are 2 eyes, so the number of clues is said to be 1 per eye for a possible total 6 clues. Generally speaking, it is not physiological possible to see clues in one eye but no clue in the other eye. Furthermore, the clues’ themselves are “ascending.” This mends that the first threshold clue is LSP, then Distinct, and then Onset. If you have Onset you MUST have LSP and Distinct, and if you have Distinct you must have LSP, but the reverse is not true due to the fact that the number of clues indicate a likelihood of the possibility of being over a specific Blood Alcohol Level. Put another way, if you LSP you may not have the remaining clues, which means you have a chance of being above a .02 BAC, but not more than .04. If you have LSP AND Distinct, but no Onset then you have a percentage of being above a .04, but under .08, whereas having all 6 clues (1 clue per eye) then there is a 77% chance you are at or above .08. These numbers are validated by laboratory research under controlled alcohol intake conditions along with strict adherence to NHTSA standards.

As a result of this test, it may be used, if done in strict compliance with NHTSA, as evidence that the subject consumed alcohol. Washington DUI case law from the State Supreme Court Mandates that at least this test, HGN, be done in complete compliance with NHTSA standards, and if so, it can be used as “evidence of consumption” only.

Other states permit the use of this test, as well as the other tests described here, for purposes other than consumption, in fact some allow it to be used as evidence of “impairment.” The tests have never been validated for this use. This information is applicable to Washington DUI cases only.

Many courts in Washington permit the use if this test for consumption evidence regardless of the officer’s compliance with the standards. Right or wrong, once described and admitted to a jury they tend to place a heavy emphasis on this test. Therefore knowledge of the test standards, correct application and limitations is critical to every DUI defense when this test is to be used.

Vertical Gaze Nystagmus

Vertical Gaze Nystagmus (VGN) is another method of determining consumption via the eyeballs and it is typically done after the HGN. The person doing the test will simply turn the stimulus sideways at the completion of the HGN test. The stimulus will then be raised vertically until the subjects eyes are looking as high as they can. During this time the eyeballs may involuntarily jerk as they travel upwards. There is no validation studies for this test. There is no scientific body of evidence that suggests this test is a reliable indicator of consumption other than extending the principles of HGN to the vertical realm. However, it is widely believed that the presence of VGN indicates a high dose of alcohol in the system of the subject. It is also believed by law enforcement to be an indicator of drug categories. VGN is typically relied upon by Drug Recognition Evaluators (DRE), despite the lack of scientific evidence.

Walk And Turn

The second test of the battery is the Walk and Turn test. Commonly described as “walk the line,” or “Walk a straight line.” This field test is, in my opinion, is the most instructionally intense test and is a test where the officer can actually cause a person to fail. In my experience this test is reported to me by clients, and also captured on video, as being improperly demonstrated and instructed. Problem is, without video evidence (most officer’s do not have video/audio recording equipment in their patrol cars) the test administration and performance is described by the officer and the accused is deemed to have an unfit memory and too much of a bias and interest to be believed over an officer.

This test is broken into two phases: the instructional phase and the walking phase.

Instructional Phase

Instructional Phase is where the officer will place the person in the standardized stance of right foot in front of left touching heel to toe keeping the arms at their sides. The person is required to maintain this position until the officer instructs the person as to how to do this test as well as demonstrate and provide an opportunity to ask clarifying question. If the person happens to step from this position (uncomfortable, nervous, physically unable to maintain this stance or any reason) that is counted as 1 clue against. The clue is called (Cannot Keep Balance”). It only takes 2 clues to fail this test so a person is halfway to failure already and they have not even begun the walking phase yet. From the manual: During this phase the officer must have the suspect assume the heel-to-toe stance by giving the following verbal instructions, accompanied by demonstrations:

  • “Place your left foot on the line” (real or imaginary). Demonstrate.
  • “Place your right foot on the line ahead of the left foot, with heel of right foot against toe of left foot.” Demonstrate.
  • “Place your arms down at your sides.” Demonstrate.
  • “Keep this position until I tell you to begin. Do not start to walk until told to do so.”
  • “Do you understand the instructions so far?” (Make sure suspect indicates understanding.)

Once the person is placed in this position there is a required demonstrations and instructions for the Walking Stage. The officer is required to “explain the test requirements, using the following verbal instructions, accompanied by demonstrations:”

  • “When I tell you to start, take nine heel-to-toe steps, turn, and take nine heel-to- toe steps back.” (Demonstrate 3 heel-to-toe steps.)
  • “When you turn, keep the front foot on the line, and turn by taking a series of small steps with the other foot, like this.” (Demonstrate).
  • “While you are walking, keep your arms at your sides, watch your feet at all times, and count your steps out loud.”
  • “Once you start walking, don’t stop until you have completed the test.”
  • “Do you understand the instructions?” (Make sure suspect understands.)
  • “Begin, and count your first step from the heel-to-toe position as ‘One.'”

It is only after explaining this test in this exact manner using these exact phrases, and language is the test properly explained.

If during this instruction phase, an officer pauses long enough that it seems as if the instructions are done a person will start. Or if the person chooses to take a “practice step” during the instruction phases this is another clue to be used against you. The clue is called “Starts Too Soon.” In fact, if this happens, AND you start too soon as described earlier, these 2 “clues” indicate you have already failed this test. The threshold for the test is 2 of 8 possible clues. Any combination of 2 is a fail. This is one of the few tests in the world where a score of 98% is considered a fail.

Once this instructional phase is done the person is provided an opportunity to ask questions. If there questions the officer must re-instruct using the same language. Once done, or if there are no questions, the person is allowed to begin. The intense instructions are a problem when a suspected DUI driver is less than fluent in the English language. Unfortunately, even when English is a second language and it is clear, there are no accommodations made for the person and they are expected to complete the test as instructed.

Walking Phase

The actual test requires a solid straight line and if one is not available the person is required to “imagine” this line. I have always wondered how wide my imaginary line is versus the officer’s imaginary line is? This is important because the clues that are looked for are: Misses Heel to Toe (a gap of ½ inch or more), Steps Off Line(foot has to be completely off and not just sideways on the line), Raises Arms (hands raised more than 6 inches from side of legs), Improper Number Of Steps, which leads to the clue for Improper Turn (any type of turn that is not as instructed), Stops Walking (the person must actually stop rather than take a slow step).

These clues can also be “Double Dipped.” For instance, a person who steps off the line on step 5, and also during that same step catches their balance by raising their arms, has just failed as they now have a score of 2! Footwear will cause footing issues. The weather, the slope of the roadside, trucks going by at freeway speeds with gusts of wind, cars driving by, these can and do all contribute to the test performance. Officers are trained to tell the person that these factors will all be taken “into consideration” but that is just a phrase to get the person to do these tests. There is NO WAY to factor these issues into and the reality is it will be used against the person.

This is not a timed test, not a test of counting, nor even a balance test despite the tricky “tightrope walker” stance; rather, it is a divided attention task. By providing numerous instructions requiring a person to watch, listen and then perform without being able to ask questions along the way requires dividing ones attention. The problem with this type of tests is fails to account for the manner in which people learn, and even more problematic is that a large portion of the driving population suffers from ADD/ADHD. Anyone who is aware of the learning limitations associated with this ADA recognized disability knows that stress and distracting circumstances will greatly affect the person’s learning ability even if the instructions appear straight forward enough. In fact, the test does not account for this disability and many more such as deafness, vertigo, inner ear issues, to name a few.

Unfortunately, the nexus between the tests and driving is created by the fact that driving is a divided attention task. In fact is a “complex divided attention task” as will be the testimony of State toxicologist in DUI trials. Therefore, 2 clues means you have the inability to properly divide attention.

One Leg Stand (OLS)

The OLS is the third and final test of the 3 learned and usually given at the roadside, although the manner in which they are learned has no bearing on the manner in which they are to be administered. The OLS requires a dry, level surface. The person is told to stand with feet together and hands at their side and the officer continues to provide further instructions. Again from the NHTSA Manual, the person is instructed in the following manner:

Initiate the test by giving the following verbal instructions, accompanied by demonstrations.

  • “Please stand with your feet together and your arms down at the sides, like this.” (Demonstrate)
  • “Do not start to perform the test until I tell you to do so.”
  • “Do you understand the instructions so far?” (Make sure suspect indicates understanding.)
  • “When I tell you to start, raise one leg, either leg, approximately six inches off the ground, foot pointed out.” (Demonstrate one leg stance.)
  • “You must keep both legs straight, arms at your side.”
  • “While holding that position, count out loud in the following manner: “one thousand and one, one thousand and two, one thousand and three, until told to stop.” (Demonstrate a count, as follows: “one thousand and one, one thousand and two, one thousand and three, etc.” Officer should not look at his foot when conducting the demonstration – OFFICER SAFETY.)
  • “Keep your arms at your sides at all times and keep watching the raised foot.”
  • “Do you understand?” (Make sure suspect indicates understanding.)
  • “Go ahead and perform the test.” (Officer should always time the 30 seconds. Test should be discontinued after 30 seconds.)

Observe the suspect from a safe distance. If the suspect puts the foot down, give instructions to pick the foot up again and continue counting from the point at which the foot touched the ground. If the suspect counts very slowly, terminate the test after 30 seconds.

Once again, this test, like ALL SFSTs is a VOLUNTARY test and the law in Washington requires telling the person this in some manner. Since it is voluntary, it is best to not do this or any of the roadside tests as is your right.

Once instructed, the person begins the tests when they are ready and the officer MUST time and observe the test. Many officers do not time this test which is a violation of the NHTSA standards.

During this timed test, the officer is looking for four clues. The clues are: Puts Foot Down (some officers will add instructions that makes it sound as if doing this is o.k.), Sways (has to be noticeable), Hops, Raises Arms (As in the Walk and Turn, must be more than 6 inches). The clues can ONLY be counted if they take place during the 30 seconds of the test. This is the importance of timing. Real time controls whether it is a clue or not, rather than relying on the person’s count. A slow counting person may not exhibit any clues during real time, but an officer who relies on the person’s count may count clues outside the actual 30 seconds and once again, 2 or more is a fail and they are susceptible to the Double Dip.

As one can see, doing these tests under the stress filled “pre-arrest” circumstances is less than ideal. These tests were validated using near laboratory settings, and transferring this out onto the roadside is possible, but requires strict adherence to the NHTSA protocols and standards. Failure to do this increases the risk of not only assigning a failing grade, but leads to an arrest for DUI. Since doing these tests, in my experience ALWAYS leads to an arrest, even for people who provide breath samples after the fact as low as .02 up to .07 the best course of action is to politely decline. In the end, it is my opinion that declining the tests, or doing the tests will lead to you being placed under arrest for suspicion of DUI. It is Hobson’s situational choice. However, declining the tests will make you case easier to defend than if you do these tests.

The best way to avoid a DUI is simply not drink and drive, but since the reality is that it is legal to do so, if you ever find yourself in the situation where you are being asked to do “some voluntary field sobriety tests, to determine if it is safe for you to drive” know this: They are voluntary and it is your right to decline them but brace yourself for an immediate arrest. However, you can take comfort in the fact that an experienced and knowledge DUI lawyer like me will be have a slightly easier time with your DUI defense than if you do the tests.