For finding a shortest path in a network bidirectional A* is a widely known algorithm. This algorithm distinguishes between the main phase and the postprocessing phase. The version of bidirectional A* that is considered the most appropriate in literature hitherto, uses a so-called balanced heuristic estimate. This type of heuristic is chosen, as it accounts for a short postprocessing phase. In this paper, we do not restrict ourselves any longer to balanced heuristics. First, we introduce an algorithm containing a new method for the postprocessing phase, reducing this phase considerably for non-balanced heuristics. For a balanced heuristic the new algorithm is nearly equivalent to the existing versions of bidirectional A*. An obvious choice for a non-balanced heuristic turns out to be superior in terms of storage space and computation time. Second, we show that the main phase on its own, when using this non-balanced heuristic estimate, is a useful algorithm, which provides us quickly with a feasible approximation.

Additional Metadata
Keywords Bidirectional search, Road network search, Shortest path
Persistent URL dx.doi.org/10.1016/j.ejor.2008.09.032, hdl.handle.net/1765/14267
Citation
Pijls, W.H.L.M., & Post, H.. (2008). A new bidirectional search algorithm with shortened postprocessing. European Journal of Operational Research, 198(2), 363–369. doi:10.1016/j.ejor.2008.09.032