Refreshment of the shortest path cache with change of single edge

Abstract

The problem of caching shortest paths has been widely studied. All of existing methods that address this problem assume that the condition of road networks does not change with time. In this paper, we study how to refresh a cache when one edge of the underlying road network (graph) changes. A bitmap-based cache structure is proposed to store and give access to shortest paths. In the following, algorithms are developed to detect shortest paths that are affected by the change of edge. After detecting affected paths, several heuristic-based refreshment strategies are proposed to update the cache. We have conducted a series of experiments to compare the performance of proposed strategies. It shows that replacing affected shortest paths with new paths whose benefit values are the largest should be applied in the shortest path caching applications such as navigation and map services.