Abstract: This paper proposes a new index structure to efficiently store and retrieve the past，present and future positions of moving objects in networks，L2R-Tree.The index structure consistes of two-level 2D R-tree and a linklist.The two-level R-trees are used to index polyline and objects’ movements along the polylines.The present positions and future prediction trajectories of moving objects are stored in linklist.L2R-Tree can not only support the trajectories query of moving objects in road networks but also is especially easy to query all the moving objects in the same route by lengthways list.Moreover，point query and range query are implemented based on this index structure.Finally，experimental studies indicate that the L2R-tree index outperformed TPR-tree in index creation as well as in querying.

摘要： 为了能有效地实现网络中移动对象的过去、当前和将来轨迹的查询，提出了一种L2R索引，它由两层R树和一个链表结构组成。两层R树用以索引道路网络和移动对象过去的运动，对象当前的位置和将来的预测轨迹信息保存在链表中。L2R索引不仅可以支持网络中的移动对象的轨迹查询，尤其是可方便的在纵向链表中查询在同条路线上的所有对象。在此索引基础上文中实施了对移动对象的范围查询和点查询，最后通过实验表明L2R结构的索引和查询性能均要优越于TPR树。