Route planning with flexible edge restrictions

In this work, we explore a new type of flexible shortest-path query, in which the query can be dynamically parameterized to constrain the type of edges that may be included in the resulting shortest path (e.g., find the shortest path in a road network that avoids toll roads and low overpasses, respective of the specified vehicle height). We extend the hierarchical preprocessing technique known as Contraction Hierarchies to efficiently support such flexible queries. We also present several effective algorithmic optimizations for further improving the overall scalability and query times of this approach, including the addition of goal-directed search techniques, search space pruning techniques, and generalizing the constraints of the local search. Experiments are presented for both the North American and the European road networks, showcasing the general effectiveness and scalability of our proposed methodology to large-scale, real-world graphs.