Abstract: Route searching in the public transit network is a key matter for the intelligent transportation system. Traditional complicated Graph Theory-based algorithm costs too much on space and time within a big scale public transportation network. The public transit network can be reduced to the logic relation, and the route searching can be reduced to the set algorithm. Thinking about the route searching system characteristics, the algorithm is based on the direction. This searching algorithm based on orderly spreaded two-dimensional set can be implemented by the means of the relational database, in conclusion, this algorithm is easy, flexible, effective in big scale network and with high practical value.

Key words: spreaded set algorithm, relational algebra, public transportation network, route searching