[Abstract] Nowadays we should research more ideas on effective usage of our road spaces for transportation planning. We proposed the practical software of micro traffic simulation based on Petri nets in our previous paper. On this simulator, the road space is divided into blocks and vehicle's advance to the forward block is modeled by a visual Petri net composed of place, transition and token . Here, places are defined as corresponding to space occupations. In this paper, we add menu on insert of background image to this simulator and show a method for construction of traffic flow net model for its background image . And applying to simulation of bus priority alternative near bus terminal area, we practice its net model build on real image of the site and demonstrate how buses always queue at the front position though one signal cycle .[keywords] transportation planning, bus priority alternative, micro traffic simulation , improvement of software.