The licensing decision for persons with medical problems has traditionally been based on empirical judgment, generally with no research findings to justify the cut-off limits which are used. The problems of emotional illness have been particularly difficult to define, especially when the reporting physician has been asked to list diagnoses, i.e. depression, schizophrenia, etc., with little correlation between the severity of the condition and driving impairment.

For the past two years Wisconsin has been using a reporting form based on functional behavioral conditions believed to be most closely related to driving impairment -suicidal, homicidal, assaultive. This paper reports on a three months' study of this approach and an assessment of its use.