A Systematic Literature Review of A* Pathfinding

A* is a search algorithm that has long been used in the pathfinding research community. Its efficiency, simplicity, and modularity are often highlighted as its strengths compared to other tools. Due to its ubiquity and widespread usage, A* has become a common option for researchers attempting to solve pathfinding problems. However, the sheer amount of research done on the topic makes it difficult to know where to start looking. With this paper, we hope to create an accessible, up to date reference on the current state of the A* search algorithm for future pathfinding projects to consider. This paper examines A-Star’s current usage in the field of pathfinding, comparing A* to other search algorithms. It also analyzes potential future developments for A-Star’s development. A* cannot keep up with the demands of current pathfinding problems. Other algorithms can maintain the same performance while also demanding less overhead and this problem only grows worse as grid size increases. However, use of innovative modifications such as different heuristic types or secondary components to the algorithm allow A* to achieve very fast times with good accuracy when dealing with large maps, while only having slightly increased overhead costs for the modifications. While beginning to show its age, improved algorithms based on the classic A* algorithm are more than capable of keeping up with modern pathfinding demands. These derivative search algorithms such as HPA* is used to overcome the limitations of A*. HPA* can compete with and even surpass its competitors depending on the challenge faced.