Population-based hospital emergency department data on motor vehicle traffic trauma in Rhode Island, 1984-85, are analyzed by age, sex, and road-use status. Annualized rates of overall and severe trauma were 1,195 cases (95% confidence interval [CI] = 1,164, 1,225) and 102 cases (95% CI = 94, 111) per 100,000 population, respectively. Overall and severe rates peaked at ages 15-24 years. Male rate excesses were most pronounced for motor-cycle and pedal cycle trauma.