I have two observations now that I am certified to administer the Standardized Field Sobriety Test (SFST). First, the test is very difficult to perform, even for a perfectly healthy and sober individual. The test is physically challenging, particularly the One-Leg-Stand. The “divided attention” component of the test makes it difficult to follow complex instructions while performing the physical tasks.
Second, however difficult it is to perform the test, it is even more difficult to administer, particularly for a poorly trained police officer operating under less than ideal conditions. And, as the National Highway Traffic Safety Administration manual itself points out, any problem with the test’s administration severely undermines confidence in the result.