A separate study was performed as part of a major traffic accident causation project to investigate the differences between drivers who caused or increased the severity of accidents and those who were innocently involved. Statistical tests were employed to evaluate age, driving experience, vehicle familiarity, road area familiarity, and driving exposure differences between male and female "at fault" and innocent accident-involved drivers. Female "at fault" drivers were characterized as having none to moderate road area familiarity, less driving experience than would be expected for their age, and being under 25 years old or between the ages of 45 and 54. Male "at fault" drivers were characterized as having little road area familiarity, having less familiarity with their vehicles than would be expected for their age, and being young (15-19) or old (over 64). Procedures for controlling measurements of driving experience, exposure, and vehicle familiarity for the effects of driver age and sex are discussed.