
Cedar Rapids OWI Lawyer: Are standardized field sobriety tests pass-fail?
by David A. Cmelik Law PLC
Contrary to some law enforcement officers, the standardized field sobriety tests are not pass-fail tests. They are more nuanced than that.
In Iowa, the tests are intended to establish reasonable grounds to believe that a test subject is intoxicated sufficiently to request a preliminary, or, portable, breath test and further invoke implied consent and request a bodily specimen back at the stationhouse.
Many law criminal complaints and law enforcement narratives have stated that a test subject “failed” these tests. But if they are not pass-fail, how can a law enforcement officer say that they are?
Some history is in order. The SFSTs are a creature of the federal transportation agency, called, the National Highway Traffic Safety Administration, or, NHTSA. This federal agency commissioned studies in California and Colorado to standardize and, frankly, to legitimate the administration of roadside tests in drunk driving prosecutions, to assist law enforcement officers in that process and help them and prosecutors present their conclusions to judges and juries in the course of OWI (DUI) litigation in a credible way.
These studies suggest that for each SFST—including the Horizontal Gaze Nystagmus (HGN), the Walk and Turn (WAT), and the One Leg Stand (OLS), there are number of clues that someone over the presumptive legal limit of intoxication will demonstrate in order to contribute to reasonable grounds to believe the subject is intoxicated. A decision point for the Walk and Turn is two so-called clues among a litany of eight such possible signs including:
• Cannot keep balance while listening to the instructions
• Starts too soon
• Stops while walking
• Does not touch heel to toe
• Steps off the line
• Uses arms to balance
• Improper turn
• Incorrect number of steps
The Walk and Turn, however, is by NHTSA’s own admission, only 79% effective at determining whether someone is over the presumptive legal limit of intoxication in the State of Iowa. In other words, in 100 test administrations, only 79 of the 100 test subjects who demonstrates two or more signs correlated with intoxication will test over the presumptive legal limit of intoxication. That leaves 21 who show such signs are below the presumptive limit of intoxication.
The OLS is only 65% effective at determining whether someone is under the influence. Let me say that one more time. Nearly a full third who do not perform the one leg standard will test under the presumptive legal limit for intoxication in the State of Iowa.
Law enforcement officers respond in one of two ways. First, they argue that each of the tests are, individually, one of a battery of SFSTs that, taken together, provide the best available approach to determining reasonable grounds to believe a motorist is impaired at the roadside—not absolute proof. Second, on a similar note they emphasize that the process escalates to greater investigation and more reliable means to measure impairment only after such grounds are established. For example, police argue they will not ask for a PBT unless they already have reasonable grounds to believe the test subject is impaired. Iowa Code § 321J.5. From there, they may effectuate an arrest but they can also invoke implied consent and request a bodily specimen which is admissible in court to prove intoxication. Iowa Code § 321J.6. In the final analysis, law enforcement and prosecutors argue, it is for the jury to decide whether someone is under the influence in an OWI prosecution.
If you or a loved one has been arrested for OWI (DUI) in Cedar Rapids, Iowa City, Waterloo, or other Iowa community, contact David A. Cmelik Law PLC for a free initial consultation. Remember however that a blog is not legal advice and that sending unsolicited information to an attorney does not establish an attorney-client relationship.

Loaded dice? it can feel like your OWI arrest was a self-fulfilling prophesy from the moment the officer asked how much you had to drink. While conducting the Walk and Turn and One Leg Stand, you were thinking, "I can't do this sober." Your instincts were somewhat right. The WAT and OLS are not 100% effective at determining impairment. If you or a loved one has been arrested for OWI (DUI) or other offense in Cedar Rapids, Iowa City, Waterloo, or other Iowa community, contact David A. Cmelik Law PLC at 319-389-1889.