This paper illustrates the simulation method of evaluating the effect of system component changes on highway crash reduction. The evaluation procedure presented uses operating characteristics of a component as input, and compares the performance of alternative components in emergency traffic conflict situations. It is shown that Monte Carlo simulation of the model may be an efficient technique for comparing component alternatives. The examples presented involve (1) the emergency braking capabilities of two populations of vehicles in emergency car-following situations, and (2) two different rear lighting systems.