Abstract
Quality of road traffi c in Japan is still unsatisfactory as the road network cannot achieve the desirable performance corresponding to traffi c and access functions of roads yet, and there remain a lot of subjects to be resolved in terms of road design and traffi c operations. The existing road network should be gradually improved and restructured as cost-effective, high-performance one, however, the conventional highway planning and design methodology can be considered to hardly achieve it. For that, practical application of the "performance-oriented highway planning and design" policy is needed, which can flexibly adopt possible combinations of road design and traffi c operation schemes necessary for realizing target performance. In this article, for the special issue on "performance-oriented highway planning and design", its concept and research requirements are overviewed, as well as the structure of this issue.
