An exact bidirectional A ⋆ approach for solving resource-constrained shortest path problems

Abstract

Bidirectional dynamic programming is an algorithm that searches for paths in a network from both the starting and the ending nodes that optimize a given objective function. In recent years, bidirectional dynamic programming has been shown to be an effective means for solving resource-bounded shortest path problems. While many researchers have observed that bidirectional A ⋆ approaches perform poor computationally, we exploit the presence of resource constraints to overcome the source of these computational challenges. Our main contribution in this paper is an exact bidirectional A ⋆ algorithm for resource-constrained shortest path problems (RCSPPs) that is capable of solving large-sized instances that challenge the state-of-the-art in the literature. We also analyze, both computationally and theoretically, the sensitivity of the algorithm's performance to its inputs.