Safety is a crucial consideration in the design of roadways, yet formal tools to study roadway safety prior to construction are often quite limited. As a possible new tool, this work investigates the iterative use of vehicle dynamic simulations to study vehicle-roadway interaction in order to optimize highway design for safety. Following a discussion of the history and accuracy of vehicle dynamic simulations, a methodology of roadway geometry analysis is presented. This methodology is demonstrated by an example scenario studying the safety of a depressed median of a rural highway when there is an in-median incursion. The vehicle type, vehicle speed, vehicle trajectory, and the driver's corrective maneuvers are all varied in a simulation-based analysis to evaluate their respective effects on vehicle behavior including vehicle orientation, trajectory, and instabilities.