The improvement of the street system in densely built-up areas is one of the most important treatments for urban improvement. This paper deals with three case study districts in Tokyo, where advanced improvement tasks for the improvement of collective streets are carried out. Based on the survey of the housing reconstruction process along the improved streets and the demographic change of each case study district, the effects and performances of the street improvements are pointed out. Planning instruments for the built-up areas in combination with improvement of collective streets and guidance of building activity are proposed.
