According to DUIblogger Lawrence Taylor, the Horizontal Gaze Nystagmus (HGN) test is essentially a fraud. This is the follow-the-pen eye test that cops use to test drivers for impairment, and it’s one of only three tests approved by the Department of Transportation.
Taylor quotes a recent study:
This summary critique demonstrates that it is scientifically meretricious and that the United States Department of Transportation indulged in deliberate fraud in order to mislead the law enforcement and legal communities into believing the test was scientifically meritorious and overvaluing its worth in the context of criminal evidence….
A series of NHTSA studies had examined the field sobriety tests in use around the country and determined that three of them were accurate, easy to do in the field, and easy to do the same way every time: Walk and Turn, One Leg Stand, and Horizontal Gaze Nystagmus.
I’ve never been pulled over for suspected drunk driving, but I’ve thought a little about how to handle it. My plan has been to refuse to do the Walk and Turn or One Leg Stand tests because the NHTSA has only validated those tests for people in a limited weight range, and I’m well outside the bounds.
(Of course I wouldn’t say that to the cop: I don’t want him thinking about why I know so much about the tests. He’ll never believe that I was just curious and looked it up. My plan is to say something like “Stand on one leg? Oh, man, I haven’t had that kind of balance in decades!” Then if he decides to give me the breath test, I’ll just blow a straight 0.00% and be on my way—I never drink and drive. At least that’s what I’d like to do. In reality, I’ll probably just cave-in and meekly do whatever he tells me to do. I hate when that happens.)
Now it looks like I’d have to refuse the HGN test too.