A lot of residential areas in Tokyo are threatened by the trough car traffic. This paper aims to analyze the quasi-arterial road carrying the through traffic in those areas. We surveyed the density of both arterial roads and quasi-arterial roads indicated on the maps showing byroads in Tokyo 23-ku. And as the case study, we investigated Suginami area where they have a lot of quasi-arterial roads in the residential community, including the traffic accident analysis. As the result, we showed the present conditions, problems and future direction to improve such kinds of roads.
