Standardized Field Sobriety Tests

A Standardized Field Sobriety Test "SFST" is much like a roadside screening device test however it is far more revealing for the officer as the test provides clues as to the subject driver's level of impairment as opposed to simply obtaining a numeric blood alcohol concentration "BAC" indication.

SFSTs consist of three different psychophysical tests:  Horizontal Gaze Nystagmus (HGN) test; Walk and Turn Test; One Leg Stand Test.  SFSTs were proven highly reliable in clinical as well as field validation studies.  They are capable of discriminating between BAC's above and below 80 milligrams of alcohol in 100 millilitres of blood.  In fact, when administered by trained and experienced police officers SFSTs can discriminate between BAC’s above or below 50 milligrams of alcohol in 100 millilitres of blood.

Police officers are increasingly being trained in the use of SFSTs in an effort to curb impaired driving as a result of alcohol or drug use, or both.  SFST officers are not necessarily Drug Recognition Experts "DRE's".  A subject who performs poorly during the administration of the tests by an SFST officer will likely be arrested for impaired driving.  A demand to accompany for an evaluation conducted by an evaluating officer "DRE" will follow.  A minimum standard of “poor performance” is in place.

The results of a SFST test are recorded on a SFST worksheet and form part of the arresting officer’s evidence.  The way in which the worksheet is scored is standardized, recognizable and can be interpreted by any SFST trained or DRE officer.  Passing a SFST would not preclude on officer from administering a road side screening device test.