Improved Lightweight Rendering of Road Networks based on Contraction Hierarchies

Contraction Hierarchies (CH) are one of the most popular techniques for accelerating shortest path queries. In previous works, it has been shown that CH in principle can be instrumented to also produce variable level-of-detail renderings of road networks. Yet, the existing approach still suffers from severe drawbacks like topological inconsistencies or distortion of the overall shape of the road network, which impairs the practical usability. We significantly improve upon the existing approach both in terms of quality of the visual representation as well as query times. As a result, we obtain a lightweight augmentation of the CH data structure that allows for very efficient and visually pleasing rendering of massive road network data.