A New Hampshire man recently was found not guilty on a DUI charge based upon failed field sobriety tests.  Critics have cried foul. However, a careful review of police officer training manuals produced by the National Highway Transportation Safety Administration cries ‘fair.”

The alleged DUI driver’s defense was that he was obese and the field sobriety tests should not have been performed in the first place.  NHTSA has developed 3 standardized field sobriety tests including the HGN (eye jerking test), the walk and turn test and the one-leg stand to estimate blood alcohol content and to aid DUI police officers in making DUI arrest decisions.

The one-leg stand and walk and turn test is divided into attention tests which measure one’s ability to follow instructions and physical dexterity while performing a physical task.  Initial studies indicated that the HGN was 77% effective, the walk and turn were 68% effective and the one-leg stand was 66% effective under ideal conditions in an indoor environment, using a random sample of people and not on the side of the highway.

Testing on the highway is impaired as the ground is not always “reasonably dry, hard, level, [debris free] and non-slippery.”  Further, these studies intentionally did not test those over 65 years of age, with back, leg, or middle ear problems, or people who are over-weight by 50 pounds or more as these people had difficulty with sobriety tests when they were not drinking.  These restrictions are not “fiction” as “watchdog” groups like MADD claim but come from the NHTSA field sobriety training manual used by law enforcement officers all across the country and are quoted from the training manual used by Georgia DUI Police officers.