Geoscience Reference
In-Depth Information
Evaluation of Properties to determine the
Importance of individual Roads for Map
Generalization
Qi Zhou, Zhilin Li
Department of Land Surveying and Geo-Informatics, The Hong Kong Polytechnic
University, Hong Kong, China
sevenlaand@hotmail.com
Abstract
Many researchers have paid much attention to the importance of individual
roads for various applications such as traffic flow analysis and road net-
work generalization. This paper gives a comparative analysis of different
properties to determine the importance of individual roads for road net-
work generalization purpose. These properties include one geometric
property (length); three topological properties (degree, closeness and
betweenness) and one thematic property (road class). Two representative
selective omission approaches (stroke-based selection and mesh density-
based elimination) are implemented to generalize road network. For each
approach, different properties are respectively used to determine the
importance of individual roads. The road network of Hong Kong Island is
used as study area for testing and two measures (similarity and connec-
tivity) are employed to evaluate the selections. Results show that, when the
stroke-based selection approach is implemented, using length performs
best in determining the importance of individual roads, and using
betweenness or closeness performs well in preserving the connectivity of
the retained network; when the mesh density-based elimination approach is
implemented, all these properties have quite similar selections.
1- Introduction
Road data is a type of infrastructural geographical data and all roads in a
given area form a network. Study of road networks has been a topic of
