Abstract: Taking into account the spatial and temporal constraints simultaneously can filter irrelevant data early and improve the efficiency of discovering spatio-temporal association rule. Based on the idea, Spatio-Temporal Apriori (STApriori) algorithm was proposed. It analyzes the time validity and spatial relativity at the same time during the gene ration of frectuency item sets. It classifies the time duration of spatio-temporal data and considers the spatial relationship firstly and generates the transaction table, then performs join operation on spatial-related item sets. Experiments illuminate that the algorithm is well performed. The algorithm is applied in intelligent transportation system to analyze the trend of traffic congestion by identifying spatio-temporal association between road sections.

Key words: Spatio-temporal constraint, Association rule, Trend of traffic congestion