Road Network Selection for Small-Scale Maps Using an Improved Centrality-Based Algorithm
JOURNAL OF SPATIAL INFORMATION SCIENCE Number 9 (2014), pp. 71–99 doi:10.5311/JOSIS.2014.9.166 RESEARCH ARTICLE Road network selection for small-scale maps using an improved centrality-based algorithm Roy Weiss and Robert Weibel Department of Geography, University of Zurich, Zurich, Switzerland Received: January 31, 2014; returned: March 13, 2014; revised: July 29, 2014; accepted: August 18, 2014. Abstract: The road network is one of the key feature classes in topographic maps and databases. In the task of deriving road networks for products at smaller scales, road net- work selection forms a prerequisite for all other generalization operators, and is thus a fun- damental operation in the overall process of topographic map and database production. The objective of this work was to develop an algorithm for automated road network selec- tion from a large-scale (1:10,000) to a small-scale database (1:200,000). The project was pur- sued in collaboration with swisstopo, the national mapping agency of Switzerland, with generic mapping requirements in mind. Preliminary experiments suggested that a selec- tion algorithm based on betweenness centrality performed best for this purpose, yet also exposed problems. The main contribution of this paper thus consists of four extensions that address deficiencies of the basic centrality-based algorithm and lead to a significant improvement of the results. The first two extensions improve the formation of strokes concatenating the road segments, which is crucial since strokes provide the foundation upon which the network centrality measure is computed. Thus, the first extension en- sures that roundabouts are detected and collapsed, thus avoiding interruptions of strokes by roundabouts, while the second introduces additional semantics in the process of stroke formation, allowing longer and more plausible strokes to built.
[Show full text]