关键词: 公共交通, 换乘, 有向图, 最短路径

Abstract: For the public transport query system，the passengers sometimes take into consideration multiple factors such as transfers，distance，expenses，type of lines etc.Therefore a travel route query model needs to support multiple level goals.Therefore based on the direct graph with weights，a new query model which satisfies multiple query requirements by changing weights is defined，and the strategy of assigning weights is discussed according to travel route query that satisfies three level requirements including the least transfer，prior ride condition and the minimal stops.Experiment show that the model proposed is effective，available as well as good flexibility.

Key words: public transport, transfer, direct graph, shortest path