An evacuation plan helps people move away from an area or a building. To achieve a fast evacuation, we present an algorithm to compute the optimal route for each local region. The idea is to reduce congestion and to maximize the number of evacuees arriving at exits in every time span. Our system considers the crowd distribution, exit locations, and corridor widths when determining the optimal routes. It also simulates crowd movements during the route optimization. To implement this idea, we expect that neighboring crowds who take different evacuation routes should arrive at respective exits nearly at the same time. If this is not the case, our system updates the routes of the slower crowds. Given that crowd simulation is non-linear, the optimal route is computed in an iterative manner. The process repeats until an optimal state is achieved. Experiment results demonstrate the feasibility of our evacuation route optimization.