Abstract: The road public traffic network is optimized based on the development mode of road transit supporting for the urban rail transit. The studied area is classified according to the rail transit impact factor. Taking supply and demand equilibrium and the minimization of passengers travel costs as the objectives, a bi-level optimization model is developed based on the road transit four dimensions effective factors including the effective section transit volume, generalized ticket fare, service time and environment cost. Genetic algorithm with restrictions is used to solve the proposed model. The proposed bi-level model and algorithm are used to optimize the road public traffic network based on the metro 1, 2 in Chengdu. Application results show that the optimization network increase the passengers of subway network and especially reduce the invalid competition between the road transit and rail transit along the corridor. Outcomes of this research can provide decision support of the development mode of road transit supporting for the urban rail transit.