Index in Road Network

Moving object data in road network is a complex data type, including not only static spatial road network information, but also the dynamic spatio-temporal information. Therefore, road network query is an operation with a high time and space complexity. Efficient indexing mechanism is an effective solution to improve the efficiency of data access. However, the method in this situation is different from those for objects moving in 2-D free space, because not only the moving directions but also the distance among moving objects are constrained by the road network. Therefore, the neighboring relations among moving objects should take the underlying road network into consideration.