Abstract: Overtake is a very important character of pedestrian. When people move to the destination,
they can watch the circumstances around themselves, and chose a better direction to move, rather than
turning around until they collide with other evacuee. The paper propose an effective method based on
geometrical algorithm. In this method, the each pace moving of a pedestrian is divided into three
steps. The first step is to define the vision region, and four important sight lines and three vision
regions. The second step is to counter the numbers of evacuee in each region, and compare the
density of evacuee in each region and chose the minimal one. The last step is to decide the direction
in the chosen region. Experimental results demonstrate the reality of the method.

Key words: computer application, evacuation model, geometrical method, evacuation route