A variety of systemic, neurological, psychiatric, and developmental disorders put drivers at particular risk for a car crash (Tables 46.1 and 46.2). However, medical diagnosis alone is o±en an unreliable criterion for driver certi¨cation. šousands of di¥erent medical diseases a¥ect the organ systems (circulatory, digestive, endocrine, integumentary, immune, lymphatic, musculoskeletal, nervous, reproductive, respiratory, urinary), the brain, and the mind (Table 46.3) in many di¥erent ways. Although many diseases impair performance and behavior, only a handful have been studied in any detail. Absence of evidence of unsafe driving in these understudied conditions is not evidence of absence of safety problems. Minimizing crash risk and maximizing mobility requires an understanding of how medical disorders a¥ect driver performance and behavior. By

understanding the demographics, performance, and behavior patterns that lead to driver errors that cause crashes and injuries, it may be possible to design interventions to reduce these errors and injuries and preserve mobility. šese interventions include driver performance monitoring devices, collision alerting and warning systems, road design, graded licensure strategies, and driver education, training, and rehabilitation.