Abstract
In Japan, reorganization of road network into functionally hierarchical form becomes more important so as to efficiently improve travel performance between centers where daily-life and/or urban services are provided. This study aims at investigating the appropriate composition of a functionally hierarchical road network which can achieve the target travel times set for various connections of centers in the subjective region. Here, composition is defined as a combination of the number of hierarchical road levels, target travel speed, road spacing and access spacing of each road level. In this paper, alternatives of such a composition are derived by considering the impact of road crossings as well as roadside access. At the end, a case study is conducted in Tokaido region, Japan, and travel performance indices, namely travel time and average travel speed, between various types of centers are estimated under each alternative composition of a functionally hierarchical road network. The result shows that road level with higher travel speed (i.e., 50~60km/h) can significantly work especially for the communities in peninsula and mountainous rural area by enhancing the accessibility to urban centers.
