2018 Volume 4 Issue 1 Pages A_55-A_63
In this study, we found the threshold values for the road structure conditions and others of two-lane and multilane road to permit a travel speed of 50 km/h with the goal of identifying the factors of road structures which made it impossible to achieve speed services for roads in which traffic functions and expected corresponding speed service is not achieved, and to develop the countermeasures for that purpose. In this study, we proposed an approach for analyzing the necessary and sufficient road structure conditions and based on the road traffic census data, analyzed the roads in Japan which are of a higher class than prefecture roads. And finally, we can confirm that it is likely that the obtained threshold value is able to be used for the analysis for the performance verification of the National Highway Bypass.