In this paper,a model of optimum route with the minimal transfer times as primary goal and the minimal stops or the least payment as second goal was built.

I learn that minimum transfer times are the most powerful motive for a transit trip.

A mathematic model of optimum route with minimal transfer times as primary goal and the minimal stops as the second goal was built in the paper.

Considering passengers travel psychoanalysis,the public traffic model of optimum route is proposed,which goal is minimal transfer times.

The paper presents two optimal trip path mod-els of bus passengers,aiming to the leas"ttransfer times" and the shortes"ttrip time"respectively,thus gets different optimal trip paths for bus passengers to choose their suitable trip paths.

Based on the relationship of them ,a multi-objects mathematical model of linear program was built which was designed based on the objects of the shortest distance ,the smallest transfer number of times and money .

Of them, the accessibility of public-transit is a synthetical index which decides whether the transportation system can work with high quality and efficiency, and it can be reflected by average transfer times(ATT) .

By making use of geographic information system(GIS) technology to build public transportation network model,"least transfer number" and "least travel time" for the goal of bus transfer query,a transter query system is achieved at Visual Basic 6.