What is Appreciable Impairment and Why Does it Matter?

There is a common misconception that the legal standard for Driving While Impaired (DWI) or Driving Under the Influence (DUI) is that the driver be “drunk” or the requirement that the State must only prove an alcohol concentration of 0.08.  However, in North Carolina that is simply not the circumstance in many DWI cases.  The impaired driving statute is N.C.G.S. 20-138.1 and it provides for two (2) ways that the State can demonstrate the offense of impaired driving.  The first being a BAC of 0.08 and the second a showing that the consumption of an “impairing substance” caused the defendant to lose his/her mental and/or physical faculties to such an extent that there was appreciable impairment to either or both faculties, otherwise known as “appreciable impairment”.  So what does appreciable impairment that mean and how can the State prove it beyond a reasonable doubt?

Merriam-Webster’s dictionary defines the word “appreciable” as follows: “capable of being perceived and recognized or of being weighed and appraised” and “large enough to be noticed or measured.”  The Synonym Finder (1967) lists synonyms for the word “appreciable” as follows: “material enough to be recognized, large enough to be estimated, definite, noticeable, perceptible, discernible, estimable, ascertainable, visible, apparent, distinguishable, cognizable, perceivable, sensible, detectable, evident”.  An intoxilyzer test and field sobriety tests are not necessarily required to establish one’s faculties as being appreciably impaired.  Our courts have stated that this impairing effect on a person’s mental and/or physical faculties caused by the consumption of an impairing substance must be appreciable, that is, sufficient to be recognized and estimated, for a proper finding that one was impaired at the time of driving.  State vs. Felts, 5 N.C. App. 483, 168 S.E.2d 499 (1969).

An odor of alcohol standing alone is not sufficient evidence for the State to prove impairment, but an odor of alcohol when considered in connection with bad driving or other conduct showing appreciable impairment can be sufficient prima facie evidence to show a violation of North Carolina’s impaired driving statute.  State v. Hewitt, 263 N.C. 759, 140 S.E.2d 241 (1965).  As state above, it is not necessary for someone to be drunk and operate a motor vehicle on a public highway to violate be found guilty of impaired driving.  A person can be found guilty by our courts for DWI if they have consumed some quantity of an impairing substance (alcohol, marijuana, prescription medication or some other controlled substance) whether it be a small amount or a large amount, one drink or several drinks, or one bottle of beer or one can of beer, or more than one, so cause that person to lose the normal control of their bodily or mental faculties, or both of those faculties, to such an extent that there is an appreciable impairment of either one of those faculties.  State vs. Felts, 5 N.C. App. 483, 168 S.E.2d 499 (1969).

The State utilizes various methods to train law enforcement officers to recognize and measure appreciable impairment during a DWI investigation and arrest.  Most notably, the National Highway Traffic Safety Administration also known as “NHTSA” has developed standardized field sobriety tests to assist officers in making decisions related to impaired driving enforcement.  NHTSA claims that these “cues” provide law enforcement officers with useful and scientifically valid information concerning the behaviors that are most predictive of impairment.  Based upon several indicators observed by law enforcement, from the driving of the motor vehicle (the vehicle in motion phase) to the performance of the standardized field sobriety tests (walk and turn, one-leg stand and horizontal gaze nystagmus), these observations made by law enforcement may be used by the State in proving appreciable impairment.  It is important to note, that you are NOT required to perform any of these field sobriety tests or a roadside breath test in assisting law enforcement in collecting evidence of appreciable impairment against you.  Under North Carolina’s implied consent laws, the only test you are required to perform or face the possibility of suspension of your drivers license is a breath test usually taken following your arrest at the jail on an intoxlizyer machine and administered by a chemical analyst.

Even if you have performed field sobriety tests, under NHTSA’s study, a combination of all of these roadside tests only shows an 80% accuracy of impairment, this accuracy percentage is far from beyond a reasonable doubt and may not even be sufficient to establish probable cause to arrest in your case.  These tests are highly subjective and Raleigh DWI Attorney Chris Dozier will review all of the evidence in your case to determine whether the State properly administered these test and whether or not the officer accurately observed “appreciable impairment” in your case.  If you have been charged with a DWI in Wake County, contact Raleigh DWI Attorney Chris Dozier today for a free consultation.